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Biology Theory SLOs Grade 11-12

 

2006 National Curriculum SLOs

CAIE O&A level Curriculum 2023 - 2025 SLOs

International Bacclaurate - Diploma Programme - Biology

NCC 2023 SLOs

Guidance on NCC 2023 SLOs

Elaboration on the extent of depth of study required for the SLOs and assessment expectations

Essential Questions

Rationale

Questions for Feedback from Stakeholders

(questions are numbered according to the corresponding SLO)

Envisioned Total Number of Teaching Hours

 

 

 

 

 

 

 

 

How are Broad Topics Conceptualised

 

 

 

Cell Biology

Biomolecules

Central Dogma, Genetics and Inheritance

Enzymes

Metabolism

Ecology

Evolution

Prokaryotes, Protists and Fungi

Acellular life

Plants

Human Physiology

Neuroscience and the Endocrine System

Immunity

Diseases

Pharmacological Drugs

Biostatistics and Data Presentation

Impact of Climate Change

Advanced Biotechnology

Selected Topics

 

 

 

 

Proposed Order

Corresponding Curriculum in 2006 National Curriculum

Corresponding Curriculum in CAIE O-level Curriculum 2023-2025 SLO's

 

 

 

 

 

 

Cell Biology

Understanding• List the principles and identify the apparatus used in the techniques of fractionation, differential staining,centrifugation, microdissection, tissue culture, chromatography, electrophoresis and spectrophotometry.• Describe the terms of resolution and magnification with reference to microscopy.• Explain the use of graticule and micrometer and define the units used in micrometry.Skills(Performing and Recording)• Use graticule and micrometer to study stomata and the cells of paramecium and onionUnderstanding• Describe the locations, chemical compositions and significance of the primary and secondary cell wallsand of middle lamella.• Explain the chemical composition of plasma membrane.• Rationalize the authenticity of the fluid mosaic model of plasma membrane.• Relate the lipid foundation and the variety of proteins of the membrane structure with their roles.• Identify the role of glycolipids and glycoproteins as the cell surface markers.• Explain the role of plasma membrane in regulating cell’s interactions with its environment.Skills(Analyzing, Interpreting and Communication)• Draw and label the fluid mosaic model of plasma membrane.• Measure the size of cells by micrometry.Student will:• Describe the chemical nature and metabolic roles of cytoplasm.• Distinguish between smooth and rough endoplasmic reticulum in terms of their structures and functions.• Explain the structure, chemical composition and function of ribosome.• Describe the structure and functions of the Golgi complex.State the structure and functions of the peroxysomes and glyoxysomes in animal and plant cells.• Describe the formation, structure and functions of the lysosomes.• Interpret the storage diseases with reference to the malfunctioning of lysosomes.• Explain the external and internal structure of mitochondrion and interlink it with its function.• Explain the external and internal structure of chloroplast and interlink it with its function.• Describe the structure, composition and functions of centriole.• Describe the types, structure, composition and functions of cytoskeleton.• Explain the structure of cilia and flagella and the mechanisms of their movement.• Describe the chemical composition and structure of nuclear envelope.• Compare the chemical composition of nucleoplasm with that of cytoplasm.• Explain that nucleoli are the areas where ribosomes are assembled.• Describe the structure, chemical composition and function of chromosome.Skills(Analyzing, Interpreting and Communication)• Compare and contrast the structure and function of mitochondria with those of chloroplasts.• Compare in tabular form, the functions of organelles with the processes occurring in animals and plants.• List the structures and molecules, which can cross the nuclear envelope.(Performing and Recording)• Prepare the slides of animal and plant cells using differential staining.Understanding• List the structures missing in prokaryotic cells.• Describe the composition of cell wall in a prokaryotic cell.• Differentiate between the patterns of cell division in prokaryotic and eukaryotic cells.• Relate the structure of bacteria as a model prokaryotic cel

1 make temporary preparations of cellular material suitable forviewing with a light microscope2 draw cells from microscope slides and photomicrographs3 calculate magnifications of images and actual sizes ofspecimens from drawings, photomicrographs and electronmicrographs (scanning and transmission)4 use an eyepiece graticule and stage micrometer scale tomake measurements and use the appropriate units, millimetre(mm), micrometre (μm) and nanometre (nm)5 define resolution and magnification and explain thedifferences between these terms, with reference to lightmicroscopy and electron microscopy1 recognise organelles and other cell structures found ineukaryotic cells and outline their structures and functions,limited to:• cell surface membrane• nucleus, nuclear envelope and nucleolus• rough endoplasmic reticulum• smooth endoplasmic reticulum• Golgi body (Golgi apparatus or Golgi complex)• mitochondria (including the presence of small circular DNA)• ribosomes (80S in the cytoplasm and 70S in chloroplastsand mitochondria)• lysosomes• centrioles and microtubules• cilia• microvilli• chloroplasts (including the presence of small circular DNA)• cell wall• plasmodesmata• large permanent vacuole and tonoplast of plant cells2 describe and interpret photomicrographs, electronmicrographs and drawings of typical plant and animal cells3 compare the structure of typical plant and animal cells4 state that cells use ATP from respiration for energy-requiringprocesses5 outline key structural features of a prokaryotic cell as found ina typical bacterium, including:• unicellular• generally 1–5 μm diameter• peptidoglycan cell walls• circular DNA• 70S ribosomes• absence of organelles surrounded by double membranes6 compare the structure of a prokaryotic cell as found in atypical bacterium with the structures of typical eukaryoticcells in plants and animals7 state that all viruses are non-cellular structures with a nucleicacid core (either DNA or RNA) and a capsid made of protein,and that some viruses have an outer envelope made ofphospholipids

Understandings:• According to the cell theory, living organisms are composed of cells.• Organisms consisting of only one cell carry out all functions of life in that cell.• Surface area to volume ratio is important in the limitation of cell size.• Multicellular organisms have properties that emerge from the interaction oftheir cellular components.• Specialized tissues can develop by cell differentiation in multicellularorganisms.• Differentiation involves the expression of some genes and not others in acell’s genome.• The capacity of stem cells to divide and differentiate along differentpathways is necessary in embryonic development and also makes stem cellssuitable for therapeutic uses.Applications and skills:• Application: Questioning the cell theory using atypical examples, includingstriated muscle, giant algae and aseptate fungal hyphae.• Application: Investigation of functions of life in Paramecium and one namedphotosynthetic unicellular organism.• Application: Use of stem cells to treat Stargardt’s disease and one othernamed condition.• Application: Ethics of the therapeutic use of stem cells from specially createdembryos, from the umbilical cord blood of a new-born baby and from anadult’s own tissues.• Skill: Use of a light microscope to investigate the structure of cells andtissues, with drawing of cells. Calculation of the magnification of drawingsand the actual size of structures and ultrastructures shown in drawings ormicrographs. Understandings:• Prokaryotes have a simple cell structure without compartmentalization.• Eukaryotes have a compartmentalized cell structure.• Electron microscopes have a much higher resolution than light microscopes.Applications and skills:• Application: Structure and function of organelles within exocrine gland cellsof the pancreas and within palisade mesophyll cells of the leaf.• Application: Prokaryotes divide by binary fission.• Skill: Drawing of the ultrastructure of prokaryotic cells based on electronmicrographs.• Skill: Drawing of the ultrastructure of eukaryotic cells based on electronmicrographs.• Skill: Interpretation of electron micrographs to identify organelles anddeduce the function of specialized cells.Understandings:• Phospholipids form bilayers in water due to the amphipathic properties ofphospholipid molecules.• Membrane proteins are diverse in terms of structure, position in themembrane and function.• Cholesterol is a component of animal cell membranes.Applications and skills:• Application: Cholesterol in mammalian membranes reduces membranefluidity and permeability to some solutes.• Skill: Drawing of the fluid mosaic model.• Skill: Analysis of evidence from electron microscopy that led to the proposalof the Davson-Danielli model.• Skill: Analysis of the falsification of the Davson-Danielli model that led to theSinger-Nicolson model.Understandings:• Particles move across membranes by simple diffusion, facilitated diffusion,osmosis and active transport.• The fluidity of membranes allows materials to be taken into cells byendocytosis or released by exocytosis. Vesicles move materials within cells.Applications and skills:• Application: Structure and function of sodium–potassium pumps for activetransport and potassium channels for facilitated diffusion in axons.• Application: Tissues or organs to be used in medical procedures must bebathed in a solution with the same osmolarity as the cytoplasm to preventosmosis.• Skill: Estimation of osmolarity in tissues by bathing samples in hypotonic andhypertonic solutions. Understandings:• Cells can only be formed by division of pre-existing cells.• The first cells must have arisen from non-living material.• The origin of eukaryotic cells can be explained by the endosymbiotic theory.Applications and skills:• Application: Evidence from Pasteur’s experiments that spontaneousgeneration of cells and organisms does not now occur on EarthUnderstandings:• Mitosis is division of the nucleus into two genetically identical daughter nuclei.• Chromosomes condense by supercoiling during mitosis.• Cytokinesis occurs after mitosis and is different in plant and animal cells.• Interphase is a very active phase of the cell cycle with many processesoccurring in the nucleus and cytoplasm.• Cyclins are involved in the control of the cell cycle.• Mutagens, oncogenes and metastasis are involved in the development ofprimary and secondary tumours.Applications and skills:• Application: The correlation between smoking and incidence of cancers.• Skill: Identification of phases of mitosis in cells viewed with a microscope or ina micrograph.• Skill: Determination of a mitotic index from a micrograph.

1. Describe why cells are needed.

2. Sketch animal and plant cells.

3. Sketch the following sub-cellular organelles:

-mitochondria

-nucleus

-cell membrane

-cell wall

-proteasome

-chloroplast

- Golgi apparatus

- smooth endoplasmic reticulum

-lysosomes

-rough endoplasmic reticulum

-vesicles

-centrioles

-peroxisome

- proteasome

- vacuoles

- ribosomes

4. Describe the role and processes occurring in the following sub-cellular organelles:

-mitochondria

-nucleus

-cell membrane

-chloroplast

-lysosomes

-cell wall

-centrioles

-proteasome

- Golgi apparatus

- smooth endoplasmic reticulum

-rough endoplasmic reticulum

-vesicles

-peroxisome

- proteasome

- vacuoles

- ribosomes

5. Describe the function of cellular signaling.

6. Explain with examples different types of signaling cascades present in cells.

7. Explain how a signal from outside the cell can be enter the cell.

8. Explain how stem cells are able to differentiate into any cell type.

9. Explain different types of stem cells and compare and contrast them.

10. Explain the advantages and disadvantages of using induced Pluripotent Stem Cells.

11. Describe the theory of abiogenesis.

12. Explain which types of evidence were used to prove the theory of abiogenesis wrong.

13. Explain the structure of the cell membrane and what techniques can be sued to study it.

14. Explain how different types of substances are transported across cell membranes with diagrams.

15. Differentiate between prokaryotic and eukaryotic cells with diagrams.

16. Explain the cell theory, how to validate it and exceptions to it.

17. Explain how the electron microscope works.

18. Write the chemical structure of a single phospholipid.

19. Describe endocytosis.

20. Describe exocytosis.

21. Compare and contrast simple and facilitated diffusion.

22. Explain in great detail the steps of mitosis with diagrams.

23. Explain in great detail the steps of meiosis with diagrams.

 

Understand the utility of having a cell-type structure.

Why is it important to have sub-cellular organelles at all?

What mechanisms does the cell use to regulate its internal processes such as transport, cell division, metabolism etc?

Students must undestand how the basic unit of life - a cell - functions and its various organelles.

 

Biomolecules

Understanding• Introduce biochemistry and describe the approximate chemical composition of protoplasm.• Distinguish carbohydrates, proteins, lipids and nucleic acids as the four fundamental kinds of biologicalmolecules.• Describe and draw sketches of the dehydration-synthesis and hydrolysis reactions for the making andbreaking of macromolecule polymers.Understanding• Explain how the properties of water (high polarity, hydrogen bonding, high specific heat, high heat ofvaporization, cohesion, hydrophobic exclusion, ionization and lower density of ice) make it the cradle oflife.Skills(Analyzing, Interpreting and Communication)• Draw model diagrams to describe the hydrogen bonding.• Develop a table to align the properties of water with benefits to life.Understanding• Define carbohydrates and classify them.• Distinguish the properties and roles of monosaccharides, write their empirical formula and classify them.• Compare the isomers and stereoisomers of glucose.• Distinguish the properties and roles of disaccharides and describe glycosidic bond in the transportdisaccharides.Distinguish the properties and roles of polysaccharides and relate them with the molecular structures ofstarch, glycogen, cellulose and chitin.• Justify that the laboratory-manufactured sweeteners are “left-handed” sugars and cannot bemetabolized by the “right-handed” enzymes.Skills(Analyzing, Interpreting and Communication)• Draw the ring forms of alpha and beta glucose.• Illustrate the formation and breakage of maltose, sucrose and lactose.(Performing and Recording)• Perform Benedict’s test for reducing sugars.• Confirm the presence of starch through Iodine testUnderstanding• Define proteins and amino acids and draw the structural formula of amino acid.• Outline the synthesis and breakage of peptide linkages.• Justify the significance of the sequence of amino acids through the example of sickle cell hemoglobin.• Classify proteins as globular and fibrous proteins.• List examples and the roles of structural and functional proteins.Skills(Analyzing, Interpreting and Communication)• Draw table to illustrate different structural and functional proteins with the roles of each.• Illustrate the synthesis and breakage of peptide linkages.(Performing and Recording)• Confirm the presence of proteins through Biuret test.Understanding• Define lipids and describe the properties and roles of acylglycerols, phospholipids, terpenes and waxes.• Illustrate the molecular structure (making and breaking) of an acylglycerol, a phospholipid and aterpene.• Evaluate steroids and prostaglandins as important groups of lipids and describe their roles in livingorganisms.Skills(Performing and Recording)• Confirm the presence of lipids through Emulsion test.Understanding• Define nucleic acids and nucleotides.• Describe the molecular level structure of nucleotide.• Distinguish among the nitrogenous bases found in the nucleotides of nucleic acids.• Outline the examples of a mononucleotide (ATP) and a dinucleotide (NAD).• Illustrate the formation of phosphodiester bond.• Explain the double helical structure of DNA as proposed by Watson and Crick.• Define gene is a sequence of nucleotides as part of DNA, which codes for the formation of apolypeptide.• Explain the general structure of RNA.• Distinguish in term of structures and roles, the three types of RNA.Skills(Analyzing, Interpreting and Communication)• Draw the Watson - Crick Model of DNA.• Illustrate the formation of phosphodiester bond.(Performing and Recording)• Demonstrate the presence of nucleic acids in biological materials.(Initiating and Planning)• Hypothesize which came first, DNA or RNA.Understanding• Define conjugated molecules and describe the roles of common conjugated molecules i.e. glycolipids,glycoproteins, lipoproteins and nucleoproteins.Science Technology and Society Connections• List the career opportunities in the field of biochemistry.• Relate the role of prostaglandins in inflammation and pain with the inhibition of prostaglandin synthesisthrough the use of aspirin.• Correlate the scanning-tunneling microscope as the latest advancement for seeing the atoms of DNA

1 describe and carry out the Benedict’s test for reducingsugars, the iodine test for starch, the emulsion test for lipidsand the biuret test for proteins2 describe and carry out a semi-quantitative Benedict’s teston a reducing sugar solution by standardising the test andusing the results (time to first colour change or comparison tocolour standards) to estimate the concentration3 describe and carry out a test to identify the presence ofnon-reducing sugars, using acid hydrolysis and Benedict’ssolution1 describe and draw the ring forms of α-glucose and β-glucose2 define the terms monomer, polymer, macromolecule,monosaccharide, disaccharide and polysaccharide3 state the role of covalent bonds in joining smaller moleculestogether to form polymers4 state that glucose, fructose and maltose are reducing sugarsand that sucrose is a non-reducing sugar5 describe the formation of a glycosidic bond by condensation,with reference to disaccharides, including sucrose, andpolysaccharides6 describe the breakage of a glycosidic bond inpolysaccharides and disaccharides by hydrolysis, withreference to the non-reducing sugar test7 describe the molecular structure of the polysaccharidesstarch (amylose and amylopectin) and glycogen and relatetheir structures to their functions in living organisms8 describe the molecular structure of the polysaccharidecellulose and outline how the arrangement of cellulosemolecules contributes to the function of plant cell walls9 state that triglycerides are non-polar hydrophobic moleculesand describe the molecular structure of triglycerides withreference to fatty acids (saturated and unsaturated), glyceroland the formation of ester bonds10 relate the molecular structure of triglycerides to their functionsin living organisms11 describe the molecular structure of phospholipids withreference to their hydrophilic (polar) phosphate heads andhydrophobic (non-polar) fatty acid tails1 describe and draw the general structure of an amino acid andthe formation and breakage of a peptide bond2 explain the meaning of the terms primary structure,secondary structure, tertiary structure and quaternarystructure of proteins3 describe the types of interaction that hold protein moleculesin shape:• hydrophobic interactions• hydrogen bonding• ionic bonding• covalent bonding, including disulfide bonds4 state that globular proteins are generally soluble and havephysiological roles and fibrous proteins are generally insolubleand have structural roles5 describe the structure of a molecule of haemoglobin as anexample of a globular protein, including the formation of itsquaternary structure from two alpha (α) chains (α–globin), twobeta (β) chains (β–globin) and a haem group6 relate the structure of haemoglobin to its function, includingthe importance of iron in the haem group7 describe the structure of a molecule of collagen as anexample of a fibrous protein, and the arrangement of collagenmolecules to form collagen fibres8 relate the structures of collagen molecules and collagen fibresto their function1 explain how hydrogen bonding occurs between watermolecules and relate the properties of water to its roles inliving organisms, limited to solvent action, high specific heatcapacity and latent heat of vaporisation

Understandings:• Molecular biology explains living processes in terms of the chemicalsubstances involved.• Carbon atoms can form four covalent bonds allowing a diversity of stablecompounds to exist.• Life is based on carbon compounds including carbohydrates, lipids, proteinsand nucleic acids.• Metabolism is the web of all the enzyme-catalysed reactions in a cell ororganism.• Anabolism is the synthesis of complex molecules from simpler moleculesincluding the formation of macromolecules from monomers by condensationreactions.• Catabolism is the breakdown of complex molecules into simpler moleculesincluding the hydrolysis of macromolecules into monomers.Applications and skills:• Application: Urea as an example of a compound that is produced by livingorganisms but can also be artificially synthesized.• Skill: Drawing molecular diagrams of glucose, ribose, a saturated fatty acidand a generalized amino acid.• Skill: Identification of biochemicals such as sugars, lipids or amino acids frommolecular diagrams.Understandings:• Water molecules are polar and hydrogen bonds form between them.• Hydrogen bonding and dipolarity explain the cohesive, adhesive, thermaland solvent properties of water.• Substances can be hydrophilic or hydrophobic.Applications and skills:• Application: Comparison of the thermal properties of water with those ofmethane.• Application: Use of water as a coolant in sweat.• Application: Modes of transport of glucose, amino acids, cholesterol, fats,oxygen and sodium chloride in blood in relation to their solubility in water.Understandings:• Monosaccharide monomers are linked together by condensation reactions toform disaccharides and polysaccharide polymers.• Fatty acids can be saturated, monounsaturated or polyunsaturated.• Unsaturated fatty acids can be cis or trans isomers.• Triglycerides are formed by condensation from three fatty acids and one glycerol.Applications and skills:• Application: Structure and function of cellulose and starch in plants andglycogen in humans.• Application: Scientific evidence for health risks of trans fats and saturatedfatty acids.• Application: Lipids are more suitable for long-term energy storage in humansthan carbohydrates.• Application: Evaluation of evidence and the methods used to obtain theevidence for health claims made about lipids.• Skill: Use of molecular visualization software to compare cellulose, starch andglycogen.• Skill: Determination of body mass index by calculation or use of a nomogram.Understandings:• Amino acids are linked together by condensation to form polypeptides.• There are 20 different amino acids in polypeptides synthesized on ribosomes.• Amino acids can be linked together in any sequence giving a huge range ofpossible polypeptides.• The amino acid sequence of polypeptides is coded for by genes.• A protein may consist of a single polypeptide or more than one polypeptidelinked together.• The amino acid sequence determines the three-dimensional conformation ofa protein.• Living organisms synthesize many different proteins with a wide range offunctions.• Every individual has a unique proteome.Applications and skills:• Application: Rubisco, insulin, immunoglobulins, rhodopsin, collagen andspider silk as examples of the range of protein functions.• Application: Denaturation of proteins by heat or by deviation of pH from theoptimum.• Skill: Drawing molecular diagrams to show the formation of a peptide bond.Understandings:• Enzymes have an active site to which specific substrates bind.• Enzyme catalysis involves molecular motion and the collision of substrateswith the active site.• Temperature, pH and substrate concentration affect the rate of activity ofenzymes.• Enzymes can be denatured.• Immobilized enzymes are widely used in industry.Applications and skills:• Application: Methods of production of lactose-free milk and its advantages.• Skill: Design of experiments to test the effect of temperature, pH andsubstrate concentration on the activity of enzymes.• Skill: Experimental investigation of a factor affecting enzyme activity.Understandings:• The nucleic acids DNA and RNA are polymers of nucleotides.• DNA differs from RNA in the number of strands present, the basecomposition and the type of pentose.• DNA is a double helix made of two antiparallel strands of nucleotides linkedby hydrogen bonding between complementary base pairs.Applications and skills:• Application: Crick and Watson’s elucidation of the structure of DNA usingmodel making.• Skill: Drawing simple diagrams of the structure of single nucleotides of DNAand RNA, using circles, pentagons and rectangles to represent phosphates,pentoses and bases.Understandings:• The replication of DNA is semi-conservative and depends on complementarybase pairing.• Helicase unwinds the double helix and separates the two strands by breakinghydrogen bonds.• DNA polymerase links nucleotides together to form a new strand, using thepre-existing strand as a template.• Transcription is the synthesis of mRNA copied from the DNA base sequencesby RNA polymerase.• Translation is the synthesis of polypeptides on ribosomes.• The amino acid sequence of polypeptides is determined by mRNA accordingto the genetic code.• Codons of three bases on mRNA correspond to one amino acid in apolypeptide.• Translation depends on complementary base pairing between codons onmRNA and anticodons on tRNA.Applications and skills:• Application: Use of Taq DNA polymerase to produce multiple copies of DNArapidly by the polymerase chain reaction (PCR).• Application: Production of human insulin in bacteria as an example of theuniversality of the genetic code allowing gene transfer between species.• Skill: Use a table of the genetic code to deduce which codon(s) correspondsto which amino acid.Skill: Analysis of Meselson and Stahl’s results to obtain support for the theoryof semi-conservative replication of DNA.• Skill: Use a table of mRNA codons and their corresponding amino acidsto deduce the sequence of amino acids coded by a short mRNA strand ofknown base sequence.• Skill: Deducing the DNA base sequence for the mRNA strandUnderstandings:• Cell respiration is the controlled release of energy from organic compoundsto produce ATP.• ATP from cell respiration is immediately available as a source of energy in thecell.• Anaerobic cell respiration gives a small yield of ATP from glucose.• Aerobic cell respiration requires oxygen and gives a large yield of ATP fromglucose.Applications and skills:• Application: Use of anaerobic cell respiration in yeasts to produce ethanoland carbon dioxide in baking.• Application: Lactate production in humans when anaerobic respiration isused to maximize the power of muscle contractions.• Skill: Analysis of results from experiments involving measurement ofrespiration rates in germinating seeds or invertebrates using a respirometer.Understandings:• Photosynthesis is the production of carbon compounds in cells using lightenergy.• Visible light has a range of wavelengths with violet the shortest wavelengthand red the longest.• Chlorophyll absorbs red and blue light most effectively and reflects greenlight more than other colours.• Oxygen is produced in photosynthesis from the photolysis of water.• Energy is needed to produce carbohydrates and other carbon compoundsfrom carbon dioxide.• Temperature, light intensity and carbon dioxide concentration are possiblelimiting factors on the rate of photosynthesis.Applications and skills:• Application: Changes to the Earth’s atmosphere, oceans and rock depositiondue to photosynthesis.• Skill: Drawing an absorption spectrum for chlorophyll and an actionspectrum for photosynthesis.• Skill: Design of experiments to investigate the effect of limiting factors onphotosynthesis.• Skill: Separation of photosynthetic pigments by chromatograph.

• Introduce biochemistry and describe the approximate chemical composition of protoplasm.

• Distinguish carbohydrates, proteins, lipids and nucleic acids as the four fundamental kinds of biological molecules.

•  Describe and draw sketches of the dehydration-synthesis and hydrolysis reactions for the making and breaking of macromolecule polymers.

• Define carbohydrates and classify them.

• Distinguish the properties and roles of monosaccharides, write their empirical formula and classify them.

• Compare the isomers and stereoisomers of glucose.

• Distinguish the properties and roles of disaccharides and describe glycosidic bond in the transport disaccharides.

• Explain how the properties of water (high polarity, hydrogen bonding, high specific heat, high heat of vaporization, cohesion, hydrophobic exclusion, ionization and lower density of ice) make it the cradle of life.

• Distinguish the properties and roles of polysaccharides and relate them with the molecular structures of starch, glycogen, cellulose and chitin.

• Justify that the laboratory-manufactured sweeteners are “left-handed” sugars and cannot be metabolized by the “right-handed” enzymes.

• Define proteins and amino acids and draw the structural formula of amino acid.

• Outline the synthesis and breakage of peptide linkages.

• Justify the significance of the sequence of amino acids through the example of sickle cell hemoglobin.

• Classify proteins as globular and fibrous proteins.

• List examples and the roles of structural and functional proteins.

• Define lipids and describe the properties and roles of acylglycerols, phospholipids, terpenes and waxes.

• Illustrate the molecular structure (making and breaking) of an acylglycerol, a phospholipid and a terpene.

• Evaluate steroids and prostaglandins as important groups of lipids and describe their roles in living organisms.

• Define nucleic acids and nucleotides.

• Describe the molecular level structure of nucleotide.

• Distinguish among the nitrogenous bases found in the nucleotides of nucleic acids.

• Outline the examples of a mononucleotide (ATP) and a dinucleotide (NAD).

• Illustrate the formation of phosphodiester bond.

• Explain the double helical structure of DNA as proposed by Watson and Crick.

• Define gene is a sequence of nucleotides as part of DNA, which codes for the formation of a polypeptide.

• Explain the general structure of RNA.

• Distinguish in term of structures and roles, the three types of RNA.

• Define conjugated molecules and describe the roles of common conjugated molecules i.e. glycolipids, glycoproteins, lipoproteins and nucleoproteins.

 

How does structure affect function for biology?

How does the structure of various biomolecules enable them to carry out tehir unique and important roles?

Understanding biomolecules at a molecular level will impart students a solid understanding of how different biomolecules work and interact in living organisms. Thus this topic will give students an understanding of how life works at the molecular level.

 

Central Dogma, Genetics and Inheritance

• A gene is a heritable factor that consists of a length of DNA and influences aspecific characteristic.

• A gene occupies a specific position on a chromosome.

• The various specific forms of a gene are alleles.

• Alleles differ from each other by one or only a few bases.

• New alleles are formed by mutation.

• The genome is the whole of the genetic information of an organism.

• The entire base sequence of human genes was sequenced in the HumanGenome Project.

• Prokaryotes have one chromosome consisting of a circular DNA molecule.

• Some prokaryotes also have plasmids but eukaryotes do not.

• Eukaryote chromosomes are linear DNA molecules associated with histone proteins.

• In a eukaryote species there are different chromosomes that carry different genes.

• Homologous chromosomes carry the same sequence of genes but not necessarily the same alleles of those genes.

• Diploid nuclei have pairs of homologous chromosomes.

• Haploid nuclei have one chromosome of each pair.

• The number of chromosomes is a characteristic feature of members of a species.

• A karyogram shows the chromosomes of an organism in homologous pairs of decreasing length.

• Sex is determined by sex chromosomes and autosomes are chromosomes that do not determine sex.

• One diploid nucleus divides by meiosis to produce four haploid nuclei.

• The halving of the chromosome number allows a sexual life cycle with fusion of gametes.

• DNA is replicated before meiosis so that all chromosomes consist of two sister chromatids.

• The early stages of meiosis involve pairing of homologous chromosomes and crossing over followed by condensation.

• Orientation of pairs of homologous chromosomes prior to separation is random.

• Separation of pairs of homologous chromosomes in the first division of meiosis halves the chromosome number.

• Crossing over and random orientation promotes genetic variation.

• Fusion of gametes from different parents promotes genetic variation.

• Mendel discovered the principles of inheritance with experiments in which large numbers of pea plants were crossed.

• Gametes are haploid so contain only one allele of each gene.

• The two alleles of each gene separate into different haploid daughter nuclei during meiosis.

• Fusion of gametes results in diploid zygotes with two alleles of each genethat may be the same allele or different alleles.

• Dominant alleles mask the effects of recessive alleles but co-dominant alleles have joint effects.

• Many genetic diseases in humans are due to recessive alleles of autosomal genes, although some genetic diseases are due to dominant or co-dominant alleles.

• Some genetic diseases are sex-linked. The pattern of inheritance is different with sex-linked genes due to their location on sex chromosomes.

• Many genetic diseases have been identified in humans but most are very rare.

• Radiation and mutagenic chemicals increase the mutation rate and can cause genetic diseases and cancer.

• Gel electrophoresis is used to separate proteins or fragments of DNA according to size.

• PCR can be used to amplify small amounts of DNA.

• DNA profiling involves comparison of DNA.

• Genetic modification is carried out by gene transfer between species.

• Clones are groups of genetically identical organisms, derived from a single original parent cell.

• Many plant species and some animal species have natural methods of cloning.

• Animals can be cloned at the embryo stage by breaking up the embryo into more than one group of cells.

• Methods have been developed for cloning adult animals using differentiated cells.

1 describe the structure of nucleotides, including the phosphorylated nucleotide ATP (structural formulae are not expected )2 state that the bases adenine and guanine are purines with a double ring structure, and that the bases cytosine, thymine and uracil are pyrimidines with a single ring structure(structural formulae for bases are not expected)3 describe the structure of a DNA molecule as a double helix, including:• the importance of complementary base pairing between the 5′ to 3′ strand and the 3′ to 5′ strand (antiparallel strands)• differences in hydrogen bonding between C–G and A–T base pairs• linking of nucleotides by phosphodiester bonds4 describe the semi-conservative replication of DNA during theS phase of the cell cycle, including:• the roles of DNA polymerase and DNA ligase (knowledge of other enzymes in DNA replication in cells and different types of DNA polymerase is not expected)• the differences between leading strand and lagging strand replication as a consequence of DNA polymerase adding nucleotides only in a 5′ to 3′ direction5 describe the structure of an RNA molecule, using the example of messenger RNA (mRNA)1 state that a polypeptide is coded for by a gene and that a gene is a sequence of nucleotides that forms part of a DNA molecule2 describe the principle of the universal genetic code in which different triplets of DNA bases either code for specific amino acids or correspond to start and stop codons3 describe how the information in DNA is used during transcription and translation to construct polypeptides, including the roles of:• RNA polymerase• messenger RNA (mRNA)• codons• transfer RNA (tRNA)• anticodons• ribosomes4 state that the strand of a DNA molecule that is used in transcription is called the transcribed or template strand and that the other strand is called the non-transcribed strand5 explain that, in eukaryotes, the RNA molecule formed following transcription (primary transcript) is modified by the removal of non-coding sequences (introns) and the joining together of coding sequences (exons) to form mRNA6 state that a gene mutation is a change in the sequence of base pairs in a DNA molecule that may result in an altered polypeptide7 explain that a gene mutation is a result of substitution or deletion or insertion of nucleotides in DNA and outline how each of these types of mutation may affect the polypeptide produced

1 explain the meanings of the terms haploid (n) and diploid (2n)2 explain what is meant by homologous pairs of chromosomes3 explain the need for a reduction division during meiosis in the production of gametes4 describe the behaviour of chromosomes in plant and animal cells during meiosis and the associated behaviour of the nuclear envelope, the cell surface membrane and the spindle (names of the main stages of meiosis, but not the sub-divisions of prophase I, are expected: prophase I, metaphase I, anaphase I, telophase I, prophase II, metaphase II, anaphase II and telophase II)5 interpret photomicrographs and diagrams of cells in differentstages of meiosis and identify the main stages of meiosis6 explain that crossing over and random orientation(independent assortment) of pairs of homologouschromosomes and sister chromatids during meiosis produces genetically different gametes7 explain that the random fusion of gametes at fertilisationproduces genetically different individuals1 explain the terms gene, locus, allele, dominant, recessive, codominant, linkage, test cross, F1, F2, phenotype, genotype,homozygous and heterozygous2 interpret and construct genetic diagrams, including Punnett squares, to explain and predict the results of monohybridcrosses and dihybrid crosses that involve dominance,codominance, multiple alleles and sex linkage3 interpret and construct genetic diagrams, including Punnettsquares, to explain and predict the results of dihybrid crossesthat involve autosomal linkage and epistasis (knowledge of the expected ratios for different types of epistasis is notexpected)4 interpret and construct genetic diagrams, including Punnett squares, to explain and predict the results of test crosses5 use the chi-squared test to test the significance of differencesbetween observed and expected results (the formula for the chi-squared test will be provided, as shown in theMathematical requirements)6 explain the relationship between genes, proteins andphenotype with respect to the:• TYR gene, tyrosinase and albinism• HBB gene, haemoglobin and sickle cell anaemia• F8 gene, factor VIII and haemophilia• HTT gene, huntingtin and Huntington’s disease7 explain the role of gibberellin in stem elongation includingthe role of the dominant allele, Le, that codes for a functionalenzyme in the gibberellin synthesis pathway, and the recessive allele, le, that codes for a non-functional enzyme1 describe the differences between structural genes andregulatory genes and the differences between repressible enzymes and inducible enzymes2 explain genetic control of protein production in a prokaryoteusing the lac operon (knowledge of the role of cAMP is not expected)3 state that transcription factors are proteins that bind toDNA and are involved in the control of gene expressionin eukaryotes by decreasing or increasing the rate of transcription4 explain how gibberellin activates genes by causing thebreakdown of DELLA protein repressors, which normallyinhibit factors that promote transcription

• A gene is a heritable factor that consists of a length of DNA and influences aspecific characteristic.• A gene occupies a specific position on a chromosome.• The various specific forms of a gene are alleles.• Alleles differ from each other by one or only a few bases.• New alleles are formed by mutation.• The genome is the whole of the genetic information of an organism.• The entire base sequence of human genes was sequenced in the HumanGenome Project.Applications and skills:• Application: The causes of sickle cell anemia, including a base substitutionmutation, a change to the base sequence of mRNA transcribed from it and achange to the sequence of a polypeptide in hemoglobin.• Application: Comparison of the number of genes in humans with otherspecies.• Skill: Use of a database to determine differences in the base sequence of agene in two species.Understandings:• Prokaryotes have one chromosome consisting of a circular DNA molecule.• Some prokaryotes also have plasmids but eukaryotes do not.• Eukaryote chromosomes are linear DNA molecules associated with histoneproteins.• In a eukaryote species there are different chromosomes that carry differentgenes.• Homologous chromosomes carry the same sequence of genes but notnecessarily the same alleles of those genes.• Diploid nuclei have pairs of homologous chromosomes.• Haploid nuclei have one chromosome of each pair.• The number of chromosomes is a characteristic feature of members of aspecies.• A karyogram shows the chromosomes of an organism in homologous pairs ofdecreasing length.• Sex is determined by sex chromosomes and autosomes are chromosomesthat do not determine sex.Applications and skills:• Application: Cairns’ technique for measuring the length of DNA molecules byautoradiography.• Application: Comparison of genome size in T2 phage, Escherichia coli,Drosophila melanogaster, Homo sapiens and Paris japonica.Application: Comparison of diploid chromosome numbers of Homo sapiens,Pan troglodytes, Canis familiaris, Oryza sativa, Parascaris equorum.• Application: Use of karyograms to deduce sex and diagnose Down syndromein humans.• Skill: Use of databases to identify the locus of a human gene and itspolypeptide productUnderstandings:• One diploid nucleus divides by meiosis to produce four haploid nuclei.• The halving of the chromosome number allows a sexual life cycle with fusionof gametes.• DNA is replicated before meiosis so that all chromosomes consist of twosister chromatids.• The early stages of meiosis involve pairing of homologous chromosomes andcrossing over followed by condensation.• Orientation of pairs of homologous chromosomes prior to separation israndom.• Separation of pairs of homologous chromosomes in the first division ofmeiosis halves the chromosome number.• Crossing over and random orientation promotes genetic variation.• Fusion of gametes from different parents promotes genetic variation.Applications and skills:• Application: Non-disjunction can cause Down syndrome and otherchromosome abnormalities.• Application: Studies showing age of parents influences chances of non-disjunctionApplication: Description of methods used to obtain cells for karyotypeanalysis e.g. chorionic villus sampling and amniocentesis and the associatedrisks.• Skill: Drawing diagrams to show the stages of meiosis resulting in theformation of four haploid cells.Understandings:• Mendel discovered the principles of inheritance with experiments in whichlarge numbers of pea plants were crossed.• Gametes are haploid so contain only one allele of each gene.• The two alleles of each gene separate into different haploid daughter nucleiduring meiosis.• Fusion of gametes results in diploid zygotes with two alleles of each genethat may be the same allele or different alleles.• Dominant alleles mask the effects of recessive alleles but co-dominant alleleshave joint effects.• Many genetic diseases in humans are due to recessive alleles of autosomalgenes, although some genetic diseases are due to dominant or co-dominantalleles.• Some genetic diseases are sex-linked. The pattern of inheritance is differentwith sex-linked genes due to their location on sex chromosomes.• Many genetic diseases have been identified in humans but most are veryrare.• Radiation and mutagenic chemicals increase the mutation rate and can causegenetic diseases and cancer.Applications and skills:• Application: Inheritance of ABO blood groups.• Application: Red-green colour blindness and hemophilia as examples of sex-linked inheritance.• Application: Inheritance of cystic fibrosis and Huntington’s disease.• Application: Consequences of radiation after nuclear bombing of Hiroshimaand accident at Chernobyl.• Skill: Construction of Punnett grids for predicting the outcomes ofmonohybrid genetic crosses.• Skill: Comparison of predicted and actual outcomes of genetic crosses usingreal data.• Skill: Analysis of pedigree charts to deduce the pattern of inheritance ofgenetic diseases.Understandings:• Gel electrophoresis is used to separate proteins or fragments of DNAaccording to size.• PCR can be used to amplify small amounts of DNA.• DNA profiling involves comparison of DNA.• Genetic modification is carried out by gene transfer between species.• Clones are groups of genetically identical organisms, derived from a singleoriginal parent cell.• Many plant species and some animal species have natural methods ofcloning.• Animals can be cloned at the embryo stage by breaking up the embryo intomore than one group of cells.• Methods have been developed for cloning adult animals using differentiatedcells.Applications and skills:• Application: Use of DNA profiling in paternity and forensic investigations.• Application: Gene transfer to bacteria using plasmids makes use of restrictionendonucleases and DNA ligase.• Application: Assessment of the potential risks and benefits associated withgenetic modification of crops.• Application: Production of cloned embryos produced by somatic-cell nucleartransfer.Skill: Design of an experiment to assess one factor affecting the rooting ofstem-cuttings.• Skill: Analysis of examples of DNA profiles.• Skill: Analysis of data on risks to monarch butterflies of Bt crops.

• Define nucleic acids and nucleotides.

• Describe the molecular level structure of nucleotide.

• Distinguish among the nitrogenous bases found in the nucleotides of nucleic acids.

• Outline the examples of a mononucleotide (ATP) and a dinucleotide (NAD).

• Illustrate the formation of phosphodiester bond.

• Explain the double helical structure of DNA as proposed by Watson and Crick.

• Define gene is a sequence of nucleotides as part of DNA, which codes for the formation of apolypeptide.

• Explain the general structure of RNA.

• Distinguish in term of structures and roles, the three types of RNA.

• Associate inheritance with the laws of Mendel.

• Explain the law of independent assortment, using a suitable example.

• Express limitations in the law and its usefulness.

• State the scope of independent assortment in variation.

• Evaluate that inheritance of genes and their mixing during fertilization is based on mathematical probabilities.

• Describe the exceptions to the Mendel’s laws of inheritance.

• Explain incomplete dominance and exemplify it through the inheritance of flower color in 4 O’ clock plant.

• Differentiate between incomplete dominance and co-dominance.

• Describe multiple alleles and state the alleles responsible for the trait of ABO blood groups.

• Explain the case where two alleles have equal dominance and through the genetics of human bloodgroup of AB.

• Name the various human blood group systems.

• Associate multiple alleles with the ABO blood group system.

• Investigate the reasons for O-ve individual as the Universal donor and AB +ve as the Universal recipient.

• Describe the occurrence of some other blood group systems.

• Associate the positive and negative blood groups with the presence and absence of Rh factor.

• Justify why Rh incompatibility could be a danger to the developing foetus and mother.

• Explain Erythroblastosis foetalis in the light of antigen-antibody reaction.

• Suggest measures to counter the problem of Erythroblastosis foetalis before it occurs.

• Explain the terms; polygenic and epistasis.

• Describe polygenic inheritance, using suitable examples from plants (grain color in wheat) and animals (skin color in man).

• List at least five polygenic traits discovered in humans.

• Relate polygenic inheritance with epistasis.

• Give one example of epistasis from mammals (coat color inheritance in Labrador retrievers) and one from plants (pigment phenotype in foxgloves) and justify modified Mendelian ratios.

• Describe the terms gene linkage and crossing over.

• Explain how gene linkage counters independent assortment and crossing-over modifies the progeny.

• Exemplify the concept of gene linkage by quoting the example of wing length and width of abdomen in Drosophila melanogaster.

• Suggest why linkage could be observed / evaluated only if the number of progeny is quite large.

• Explain the XX-XY mechanism of sex determination in Drosophila and mammals.

• Describe the XX-XO and ZZ-ZW sex determination systems and evaluate by studying the karyotype.

• Identify the difference between homogametic and heterogametic conditions in the karyotype of male and female humans.

• Identify male and female individuals from the karyotype of Drosophila and man.

• Solve the genetics problems related to XX-XY, XX-XO and ZZ-ZW sex determination.

• Describe the concept of sex-linkage.• Explain the inheritance of sex-linked traits (eye color) in Drosophila.

• Describe the sex-linked inheritance of male characters due to Y-chromosome and the effect of Hollandric genes.

• Describe sex-influenced and sex-limited traits with common examples from human genetics.

• Describe the X- linked disorders with reference to the patterns of inheritance.

• Name some of the sex-linked disorders of man and drosophila.

• Critically analyze the inheritance of Haemophilia, colour blindness and muscular dystrophy

• Evaluate incomplete and co-dominance as variations of Mendel’s research.

• Derive an idea to get alternatives of blood transfusion. (reference could be made to synthesized plasmaand serum).

• Justify why a recessive blood group allele of ‘i’ is more frequent in population.

• Justify blood donation as a service to suffering humanity.

• Name and explain the techniques employed for embryonic screening e.g., Amniocentesis.

• Suggest ways to save lives through the knowledge gained in this chapter.

• Describe how the field of genetics has progressed to a more applied science.

• Justify the effectiveness of some of the treatments of haemophilia

• Critically analyze the history of chromosomal theory with reference to Correns’ work.

• Critically analyze the experiments of T. H. Morgan in support of the above-mentioned theory.

• Annotate the detailed structure of a chromosome.

• Describe the concept of gene and gene locus.

• Explain the concept of alleles as the alternative forms of a gene.

• Narrate the experimental work of Griffith and Hershey-Chase, which proved that DNA is the hereditary material.

• Describe the three models proposed about the mechanism of DNA replication.

• Narrate the work of Meselson and Stahl to justify the semi-conservative replication as the correct method of replication.

• Describe the events of the process of DNA replication.

• Explain DNA stability and variability as two characters of the replicating DNA molecule.

• Describe the central dogma of gene expression.

• Define gene and genetic code.

• Describe the characteristics of genetic code (universal, triplet, non-overlapping, degenerate, punctuated).

• Differentiate between the terms genetic code and codon.

• Explain the mechanism of transcription.

• Explain why the length of transcribed mRNA molecule (in Eukaryotes) shortens as it enters the cytoplasm for translation.

• Describe the mechanism of protein synthesis.

• State the difference between protein synthesis in prokaryotes and eukaryotes.

• Suggest possible ways in which the synthesized protein can be used within or outside a cell that synthesized it.

• State the importance of the regulation of gene expression.

• Describe the negative control of gene expression by repressor proteins.

• Describe the positive control of gene expression by activator proteins.

• Relate gene expression with introns and exons.

• Define mutation and identify various sources of mutation.

• Differentiate between natural and induced mutations and mutagens.

• Justify that most mutations are harmful.

• Rationalize that mutations might be a contributing factor towards evolution.

• Describe the symptoms, causes and possible available treatments of some of the chromosomal mutations. (Down’s, Klinefelter’s and Turner’s syndrome)

• Describe the symptoms, causes and possible available treatments of some of the gene mutations.

 

How is genetic information stored in high fidelity over the course of a cell's life and after cell division. How do variations arise in genetic information during cell division and across generations?

Learning how nucelci acids function as the informational moelcuels in biology is vital for students to understanding their roles as well as hereditary inheritance.

 

Enzymes

• Describe the structure of enzyme.

• Explain the role and component parts of the active site of an enzyme.

• Differentiate among the three types of co-factors i.e. in organic ions, prosthetic group and co-enzymes, with examples.

• Explain the mechanism of enzyme action through Induced Fit Model, comparing it with Lock and Key Model.

• Explain how an enzyme catalyzes specific reactions.

• Define energy of activation and explain through graph how an enzyme speeds up a reaction by lowering the energy of activation.

• Describe the effect of temperature on the rate of enzyme action

• Compare the optimum temperatures of enzymes of human and thermophilic bacteria.

• Describe the range of pH at which human enzymes function

• Compare the optimum pH of different enzymes like trypsin, pepsin, pepane.

• Describe how the concentration of enzyme affects the rate of enzyme action.

• Explain the effect of substrate concentration on the rate of enzyme action

• Describe enzymatic inhibition, its types and its significance.

• Name the molecules which act as inhibitors.

• Categorize inhibitors into competitive and non-competitive inhibitors.

• Explain feedback inhibition.

• Classify enzymes on the basis of the reactions catalyzed (oxido-reductases, transferases, hydrolases, isomerases, and ligases).

• Classify enzymes on the basis of the substrates they use (lipases, diastase, amylase, proteases etc).

1 state that enzymes are globular proteins that catalysereactions inside cells (intracellular enzymes) or are secreted tocatalyse reactions outside cells (extracellular enzymes)2 explain the mode of action of enzymes in terms of an activesite, enzyme–substrate complex, lowering of activation energyand enzyme specificity, including the lock-and-key hypothesisand the induced-fit hypothesis3 investigate the progress of enzyme-catalysed reactions bymeasuring rates of formation of products using catalase andrates of disappearance of substrate using amylase4 outline the use of a colorimeter for measuring the progress ofenzyme-catalysed reactions that involve colour changes1 investigate and explain the effects of the following factors onthe rate of enzyme-catalysed reactions:• temperature• pH (using buffer solutions)• enzyme concentration• substrate concentration• inhibitor concentration2 explain that the maximum rate of reaction (Vmax) is used toderive the Michaelis–Menten constant (Km), which is used tocompare the affinity of different enzymes for their substrates3 explain the effects of reversible inhibitors, both competitiveand non-competitive, on enzyme activity4 investigate the difference in activity between an enzymeimmobilised in alginate and the same enzyme free in solution,and state the advantages of using immobilised enzymes

Understandings:• Metabolic pathways consist of chains and cycles of enzyme-catalysedreactions.• Enzymes lower the activation energy of the chemical reactions that theycatalyse.• Enzyme inhibitors can be competitive or non-competitive.• Metabolic pathways can be controlled by end-product inhibition.Applications and skills:• Application: End-product inhibition of the pathway that converts threonineto isoleucine.• Application: Use of databases to identify potential new anti-malarial drugs.• Skill: Calculating and plotting rates of reaction from raw experimental results.• Skill: Distinguishing different types of inhibition from graphs at specifiedsubstrate concentration

Understandings:• Enzymes have an active site to which specific substrates bind.• Enzyme catalysis involves molecular motion and the collision of substrateswith the active site.• Temperature, pH and substrate concentration affect the rate of activity ofenzymes.• Enzymes can be denatured.• Immobilized enzymes are widely used in industry.Applications and skills:• Application: Methods of production of lactose-free milk and its advantages.• Skill: Design of experiments to test the effect of temperature, pH andsubstrate concentration on the activity of enzymes.• Skill: Experimental investigation of a factor affecting enzyme activity.

• Describe the structure of enzyme.

• Explain the role and component parts of the active site of an enzyme.

• Differentiate among the three types of co-factors i.e. in organic ions, prosthetic group and co-enzymes, with examples.

• Explain the mechanism of enzyme action through Induced Fit Model, comparing it with Lock and Key Model.

• Justify why the Induced Fit model is a better model for enzymes compared to the lock and Key model.

• Explain how an enzyme catalyzes specific reactions.

• Define energy of activation and explain through graph how an enzyme speeds up a reaction by lowering the energy of activation.

• Describe the effect of temperature on the rate of enzyme action

• Compare the optimum temperatures of enzymes of human and thermophilic bacteria.

• Describe the range of pH at which human enzymes function

• Compare the optimum pH of different enzymes like trypsin, pepsin, pepane.

• Describe how the concentration of enzyme affects the rate of enzyme action.

• Explain the effect of substrate concentration on the rate of enzyme action

• Describe enzymatic inhibition, its types and its significance.

• Name the molecules which act as inhibitors.

• Categorize inhibitors into competitive and non-competitive inhibitors.

• Explain feedback inhibition.

• Describe why it is easy to inhibit enzymes with deep, well-defined pockets and hard to inhibit enzymes having only smooth structural surfaces with no pockets.

• Classify enzymes on the basis of the reactions catalyzed (oxido-reductases, transferases, hydrolases, isomerases, and ligases).

• Classify enzymes on the basis of the substrates they use (lipases, diastase, amylase, proteases etc).

 

How does an enzyme's structure determine its function? How is an enzyme's activity regulated?

Students need to know how enzymes function as they play incredible roles in keeping difficult life processes working.

 

Metabolism

Understanding• Explain the role of light in photosynthesis.• Identify the two general kinds of photosynthetic pigments (carotenoids and chlorophylls).• Describe the roles of photosynthetic pigments in the absorption and conversion of light energy.• Differentiate between the absorption spectra of chlorophyll ‘a’ and ‘b’.• Describe the arrangement of photosynthetic pigments in the form of photosystem-I and II.• State the role of CO2 as one of the raw materials of photosynthesis.• Explain, narrating the experimental work done, the role of water in photosynthesis.• Describe the events of non-cyclic photophosphorylation and outline the cyclic photophosphorylation.• Explain the Calvin cycle (the regeneration of RuBP should be understood in outline only).Skills(Analyzing, Interpreting and Communication)• Draw the molecular structure of chlorophyll, showing the porphyrin head and the phytol tail.• Develop the graphical interpretation of the wavelengths of light along with the percentage absorption bychlorophyll ‘a’ and ‘b’.• Draw the Z-scheme for explaining the events of the light-dependent reactions.• Develop a flow chart for explaining the events of the light-independent reactions.(Performing and Recording)• Extract the leaf pigments and separate them by paper chromatography.Understanding• Explain the process of anaerobic respiration in terms of glycolysis and conversion of pyruvate into lacticacid or ethanol.• Outline (naming the reactants and products of each step of) the events of glycolysis.Illustrate the conversion of pyruvate to acetyl-CoA.• Outline (naming the reactants and products of each step of) the steps of Krebs cycle.• Explain the passage of electron through electron transport chain.• Describe chemiosmosis and relate it with electron transport chain.• Explain the substrate-level phosphorylation during which exergonic reactions are coupled with thesynthesis of ATP.• Justify the importance of PGAL in photosynthesis and respiration.• Outline the cellular respiration of proteins and fats and correlate these with that of glucose.Skills(Analyzing, Interpreting and Communication)• Draw the flow charts showing the events of glycolysis and Krebs cycle.• Illustrate the net energy output during glycolysis, oxidation of pyruvate and Krebs cycleUnderstanding• Define photorespiration and outline the events occurring through it.• Rationalize how the disadvantageous process of photorespiration evolved.• Explain the effect of temperature on the oxidative activity of RuBP carboxylase.• Outline the process of C 4 photosynthesis as an adaptation evolved in some plants to deal with theproblem of photorespiration.Skills(Initiating and Planning)• Justify why photorespiration is interference in the successful performance of the Calvin cycle.Science Technology and Society Connections• Analyze the impact of photorespiration on the agricultural yield in the tropic climates.

1 outline the need for energy in living organisms, as illustratedby active transport, movement and anabolic reactions, suchas those occurring in DNA replication and protein synthesis2 describe the features of ATP that make it suitable as theuniversal energy currency3 state that ATP is synthesised by:• transfer of phosphate in substrate-linked reactions• chemiosmosis in membranes of mitochondria andchloroplasts4 explain the relative energy values of carbohydrates, lipids andproteins as respiratory substrates5 state that the respiratory quotient (RQ) is the ratio of thenumber of molecules of carbon dioxide produced to thenumber of molecules of oxygen taken in, as a result ofrespiration6 calculate RQ values of different respiratory substrates fromequations for respiration7 describe and carry out investigations, using simplerespirometers, to determine the RQ of germinating seeds orsmall invertebrates (e.g. blowfly larvae)1 State where each of the four stages in aerobic respirationoccurs in eukaryotic cells:• glycolysis in the cytoplasm• link reaction in the mitochondrial matrix• Krebs cycle in the mitochondrial matrix• oxidative phosphorylation on the inner membrane ofmitochondria2 outline glycolysis as phosphorylation of glucose and thesubsequent splitting of fructose 1,6-bisphosphate (6C) intotwo triose phosphate molecules (3C), which are then furtheroxidised to pyruvate (3C), with the production of ATP andreduced NAD3 explain that, when oxygen is available, pyruvate entersmitochondria to take part in the link reaction4 describe the link reaction, including the role of coenzyme A inthe transfer of acetyl (2C) groups5 outline the Krebs cycle, explaining that oxaloacetate (4C) actsas an acceptor of the 2C fragment from acetyl coenzyme A toform citrate (6C), which is converted back to oxaloacetate in aseries of small steps6 explain that reactions in the Krebs cycle involvedecarboxylation and dehydrogenation and the reduction ofthe coenzymes NAD and FAD7 describe the role of NAD and FAD in transferring hydrogen tocarriers in the inner mitochondrial membrane8 explain that during oxidative phosphorylation:• hydrogen atoms split into protons and energetic electrons• energetic electrons release energy as they pass throughthe electron transport chain (details of carriers are notexpected)• the released energy is used to transfer protons across theinner mitochondrial membrane• protons return to the mitochondrial matrix by facilitateddiffusion through ATP synthase, providing energy for ATPsynthesis (details of ATP synthase are not expected)• oxygen acts as the final electron acceptor to form water9 describe the relationship between the structure and functionof mitochondria using diagrams and electron micrographs10 outline respiration in anaerobic conditions in mammals (lactatefermentation) and in yeast cells (ethanol fermentation)11 explain why the energy yield from respiration in aerobicconditions is much greater than the energy yield fromrespiration in anaerobic conditions (a detailed account of thetotal yield of ATP from the aerobic respiration of glucose is notexpected)12 explain how rice is adapted to grow with its roots submergedin water, limited to the development of aerenchyma in roots,ethanol fermentation in roots and faster growth of stems13 describe and carry out investigations using redox indicators,including DCPIP and methylene blue, to determine the effectsof temperature and substrate concentration on the rate ofrespiration of yeast14 describe and carry out investigations using simplerespirometers to determine the effect of temperature on therate of respiration1 describe the relationship between the structure ofchloroplasts, as shown in diagrams and electronmicrographs, and their function2 explain that energy transferred as ATP and reduced NADPfrom the light-dependent stage is used during the light-independent stage (Calvin cycle) of photosynthesis to producecomplex organic molecules3 state that within a chloroplast, the thylakoids (thylakoidmembranes and thylakoid spaces), which occur in stackscalled grana, are the site of the light-dependent stage and thestroma is the site of the light-independent stage4 describe the role of chloroplast pigments (chlorophyll a,chlorophyll b, carotene and xanthophyll) in light absorption inthylakoids5 interpret absorption spectra of chloroplast pigments andaction spectra for photosynthesis6 describe and use chromatography to separate and identifychloroplast pigments (reference should be made to Rf valuesin identification of chloroplast pigments)7 state that cyclic photophosphorylation and non-cyclicphotophosphorylation occur during the light-dependent stageof photosynthesis8 explain that in cyclic photophosphorylation:• only photosystem I (PSI) is involved• photoactivation of chlorophyll occurs• ATP is synthesised9 explain that in non-cyclic photophosphorylation:• photosystem I (PSI) and photosystem II (PSII) are bothinvolved• photoactivation of chlorophyll occurs• the oxygen-evolving complex catalyses the photolysis ofwater• ATP and reduced NADP are synthesised10 explain that during photophosphorylation:• energetic electrons release energy as they pass throughthe electron transport chain (details of carriers are notexpected)• the released energy is used to transfer protons across thethylakoid membrane• protons return to the stroma from the thylakoid spaceby facilitated diffusion through ATP synthase, providingenergy for ATP synthesis (details of ATP synthase are notexpected)11 outline the three main stages of the Calvin cycle:• rubisco catalyses the fixation of carbon dioxideby combination with a molecule ofribulose bisphosphate (RuBP), a 5C compound, to yieldtwo molecules of glycerate 3-phosphate (GP), a 3Ccompound• GP is reduced to triose phosphate (TP) in reactionsinvolving reduced NADP and ATP• RuBP is regenerated from TP in reactions that use ATP12 state that Calvin cycle intermediates are used to produceother molecules, limited to GP to produce some amino acidsand TP to produce carbohydrates, lipids and amino acids1 state that light intensity, carbon dioxide concentration andtemperature are examples of limiting factors of photosynthesis2 explain the effects of changes in light intensity, carbon dioxideconcentration and temperature on the rate of photosynthesis3 describe and carry out investigations using redox indicators,including DCPIP and methylene blue, and a suspension ofchloroplasts to determine the effects of light intensity and lightwavelength on the rate of photosynthesis4 describe and carry out investigations using whole plants,including aquatic plants, to determine the effects of lightintensity, carbon dioxide concentration and temperature onthe rate of photosynthesis

Understandings:• Metabolic pathways consist of chains and cycles of enzyme-catalysedreactions.• Enzymes lower the activation energy of the chemical reactions that theycatalyse.• Enzyme inhibitors can be competitive or non-competitive.• Metabolic pathways can be controlled by end-product inhibition.Applications and skills:• Application: End-product inhibition of the pathway that converts threonineto isoleucine.• Application: Use of databases to identify potential new anti-malarial drugs.• Skill: Calculating and plotting rates of reaction from raw experimental results.• Skill: Distinguishing different types of inhibition from graphs at specifiedsubstrate concentrationUnderstandings:• Cell respiration involves the oxidation and reduction of electron carriers.• Phosphorylation of molecules makes them less stable.• In glycolysis, glucose is converted to pyruvate in the cytoplasm.• Glycolysis gives a small net gain of ATP without the use of oxygen.• In aerobic cell respiration pyruvate is decarboxylated and oxidized, andconverted into acetyl compound and attached to coenzyme A to form acetylcoenzyme A in the link reaction.• In the Krebs cycle, the oxidation of acetyl groups is coupled to the reductionof hydrogen carriers, liberating carbon dioxide.• Energy released by oxidation reactions is carried to the cristae of themitochondria by reduced NAD and FAD.• Transfer of electrons between carriers in the electron transport chain in themembrane of the cristae is coupled to proton pumping.• In chemiosmosis protons diffuse through ATP synthase to generate ATP.• Oxygen is needed to bind with the free protons to maintain the hydrogengradient, resulting in the formation of water.• The structure of the mitochondrion is adapted to the function it performs.Applications and skills:• Application: Electron tomography used to produce images of activemitochondria.• Skill: Analysis of diagrams of the pathways of aerobic respiration to deducewhere decarboxylation and oxidation reactions occur.• Skill: Annotation of a diagram of a mitochondrion to indicate the adaptationsto its function.Understandings:• Light-dependent reactions take place in the intermembrane space of thethylakoids.• Light-independent reactions take place in the stroma.• Reduced NADP and ATP are produced in the light-dependent reactions.• Absorption of light by photosystems generates excited electrons.• Photolysis of water generates electrons for use in the light-dependentreactions.• Transfer of excited electrons occurs between carriers in thylakoid membranes.• Excited electrons from Photosystem II are used to contribute to generate aproton gradient.• ATP synthase in thylakoids generates ATP using the proton gradient.• Excited electrons from Photosystem I are used to reduce NADP.• In the light-independent reactions a carboxylase catalyses the carboxylationof ribulose bisphosphate.• Glycerate 3-phosphate is reduced to triose phosphate using reduced NADPand ATP.• Triose phosphate is used to regenerate RuBP and produce carbohydrates.• Ribulose bisphosphate is reformed using ATP.• The structure of the chloroplast is adapted to its function in photosynthesis.Applications and skills:• Application: Calvin’s experiment to elucidate the carboxylation of RuBP.• Skill: Annotation of a diagram to indicate the adaptations of a chloroplast toits function.

• Explain the role of light in photosynthesis

• Identify the two general kinds of photosynthetic pigments (carotenoids and chlorophylls)

• Describe the roles of photosynthetic pigments in the absorption and conversion of light energy

• Differentiate between the absorption spectra of chlorophyll ‘a’ and ‘b’

• Describe the arrangement of photosynthetic pigments in the form of photosystem-I and II.

• State the role of CO2 as one of the raw materials of photosynthesis.

• Explain, narrating the experimental work done, the role of water in photosynthesis.

• Describe the events of non-cyclic photophosphorylation and outline the cyclic photophosphorylation.

• Explain the Calvin cycle (the regeneration of RuBP should be understood in outline only.

• Explain the process of anaerobic respiration in terms of glycolysis and conversion of pyruvate into lacticacid or ethanol.

• Outline (naming the reactants and products of each step of) the events of glycolysis.Illustrate the conversion of pyruvate to acetyl-CoA.

• Outline (naming the reactants and products of each step of) the steps of Krebs cycle.

• Explain the passage of electron through electron transport chain.

• Describe chemiosmosis and relate it with electron transport chain.

• Explain the substrate-level phosphorylation during which exergonic reactions are coupled with thesynthesis of ATP.

• Justify the importance of PGAL in photosynthesis and respiration.

• Outline the cellular respiration of proteins and fats and correlate these with that of glucose.

• Define photorespiration and outline the events occurring through it.

• Rationalize how the disadvantageous process of photorespiration evolved.

• Explain the effect of temperature on the oxidative activity of RuBP carboxylase.

• Outline the process of C 4 photosynthesis as an adaptation evolved in some plants to deal with the problem of photorespiration.

 

How are important chemical reactions successfully carried out in living organisms? How are important chemical reactions regulated in living organisms?

Understanding metabolic reactions occruing inside livign organsims is necessary information to develop a holistic understanding of biology for any student.

 

Ecology

• Define biogeochemical cycles and locate the primary reservoirs of the chemicals in these cycles.• Describe water cycle in detail.• Define the terms aquifers and water table.• Describe nitrogen cycle in detail.• Define the terms of nitrogen-fixation, nitrification, de-nitrification and ammonification.• Describe productivity in terms of gross primary productivity and net primary productivity.• Explain the flow of energy in successive trophic levels.• Interpret the pyramids of number, biomass and energy.• Define ecological succession as the process through which ecosystems change from simple to complex.• Describe primary and secondary succession.• Differentiate between xerarch and hydrarch succession.• Explain the xerarch succession on a bare rock starting from the small pockets of lichens to thevegetations of flowering plants.• Describe characteristics of a population, such as growth, density, distribution, carrying capacity,minimum/viable size.• Explain, using demographic principles, problems related to the rapid growth of human populations andthe effects of that growth on future generations (e.g., relate the carrying capacity of the Earth to thegrowth of populations and their consumption of resources).• Analyze the role of the department of population welfare, government of Pakistan in controlling thegrowing population of Pakistan.

1 define the terms ecosystem and niche2 explain that biodiversity can be assessed at different levels,including:• the number and range of different ecosystems andhabitats• the number of species and their relative abundance• the genetic variation within each species3 explain the importance of random sampling in determining thebiodiversity of an area4 describe and use suitable methods to assess the distributionand abundance of organisms in an area, limited to framequadrats, line transects, belt transects and mark-release-recapture using the Lincoln index (the formula for the Lincolnindex will be provided, as shown in the Mathematicalrequirements5 use Spearman’s rank correlation and Pearson’s linearcorrelation to analyse the relationships between two variables,including how biotic and abiotic factors affect the distributionand abundance of species (the formulae for these correlationswill be provided, as shown in the Mathematical requirements)6 use Simpson’s index of diversity (D) to calculate thebiodiversity of an area, and state the significance of differentvalues of D (the formula for Simpson’s index of diversity will beprovided, as shown in the Mathematical requirements)

CORE CONTENT:

Understandings:• Species are groups of organisms that can potentially interbreed to producefertile offspring.• Members of a species may be reproductively isolated in separate populations.• Species have either an autotrophic or heterotrophic method of nutrition (afew species have both methods).• Consumers are heterotrophs that feed on living organisms by ingestion.• Detritivores are heterotrophs that obtain organic nutrients from detritus byinternal digestion.• Saprotrophs are heterotrophs that obtain organic nutrients from deadorganisms by external digestion.• A community is formed by populations of different species living togetherand interacting with each other.• A community forms an ecosystem by its interactions with the abioticenvironment.• Autotrophs obtain inorganic nutrients from the abiotic environment.• The supply of inorganic nutrients is maintained by nutrient cycling.• Ecosystems have the potential to be sustainable over long periods of timeApplications and skills:• Skill: Classifying species as autotrophs, consumers, detritivores or saprotrophsfrom a knowledge of their mode of nutrition.• Skill: Setting up sealed mesocosms to try to establish sustainability. (Practical 5)• Skill: Testing for association between two species using the chi-squared testwith data obtained by quadrat sampling.• Skill: Recognizing and interpreting statistical significance.Understandings:• Most ecosystems rely on a supply of energy from sunlight.• Light energy is converted to chemical energy in carbon compounds byphotosynthesis.• Chemical energy in carbon compounds flows through food chains by meansof feeding.• Energy released from carbon compounds by respiration is used in livingorganisms and converted to heat.• Living organisms cannot convert heat to other forms of energy.• Heat is lost from ecosystems.• Energy losses between trophic levels restrict the length of food chains andthe biomass of higher trophic levels.Applications and skills:• Skill: Quantitative representations of energy flow using pyramids of energy.Understandings:• Autotrophs convert carbon dioxide into carbohydrates and other carboncompounds.• In aquatic ecosystems carbon is present as dissolved carbon dioxide andhydrogen carbonate ions.• Carbon dioxide diffuses from the atmosphere or water into autotrophs.• Carbon dioxide is produced by respiration and diffuses out of organisms intowater or the atmosphere.• Methane is produced from organic matter in anaerobic conditions bymethanogenic archaeans and some diffuses into the atmosphere oraccumulates in the ground.• Methane is oxidized to carbon dioxide and water in the atmosphere.• Peat forms when organic matter is not fully decomposed because of acidicand/or anaerobic conditions in waterlogged soils.• Partially decomposed organic matter from past geological eras wasconverted either into coal or into oil and gas that accumulate in porous rocks.• Carbon dioxide is produced by the combustion of biomass and fossilizedorganic matter.• Animals such as reef-building corals and mollusca have hard parts that arecomposed of calcium carbonate and can become fossilized in limestoneApplications and skills:• Application: Estimation of carbon fluxes due to processes in the carbon cycle.• Application: Analysis of data from air monitoring stations to explain annualfluctuations.• Skill: Construct a diagram of the carbon cycleUnderstandings:• Carbon dioxide and water vapour are the most significant greenhouse gases.• Other gases including methane and nitrogen oxides have less impact.• The impact of a gas depends on its ability to absorb long wave radiation aswell as on its concentration in the atmosphere.• The warmed Earth emits longer wavelength radiation (heat).• Longer wave radiation is absorbed by greenhouse gases that retain the heatin the atmosphere.• Global temperatures and climate patterns are influenced by concentrationsof greenhouse gases.• There is a correlation between rising atmospheric concentrations of carbondioxide since the start of the industrial revolution 200 years ago and averageglobal temperatures.• Recent increases in atmospheric carbon dioxide are largely due to increasesin the combustion of fossilized organic matter.Applications and skills:• Application: Threats to coral reefs from increasing concentrations of dissolvedcarbon dioxide.• Application: Correlations between global temperatures and carbon dioxideconcentrations on Earth.• Application: Evaluating claims that human activities are not causing climatechange.

OPTION C:

Understandings:• The distribution of species is affected by limiting factors.• Community structure can be strongly affected by keystone species.• Each species plays a unique role within a community because of the uniquecombination of its spatial habitat and interactions with other species.• Interactions between species in a community can be classified according to their effect.• Two species cannot survive indefinitely in the same habitat if their niches are identical.Applications and skills:• Application: Distribution of one animal and one plant species to illustrate limits oftolerance and zones of stress.• Application: Local examples to illustrate the range of ways in which species caninteract within a community.• Application: The symbiotic relationship between Zooxanthellae and reef-buildingcoral reef species.• Skill: Analysis of a data set that illustrates the distinction between fundamentaland realized niche.• Skill: Use of a transect to correlate the distribution of plant or animal species withan abiotic variableUnderstandings:• Most species occupy different trophic levels in multiple food chains.• A food web shows all the possible food chains in a community.• The percentage of ingested energy converted to biomass is dependent onthe respiration rate.• The type of stable ecosystem that will emerge in an area is predictable basedon climate.• In closed ecosystems energy but not matter is exchanged with thesurroundings.• Disturbance influences the structure and rate of change within ecosystems.Applications and skills:• Application: Conversion ratio in sustainable food production practices.• Application: Consideration of one example of how humans interfere withnutrient cycling.• Skill: Comparison of pyramids of energy from different ecosystems.• Skill: Analysis of a climograph showing the relationship betweentemperature, rainfall and the type of ecosystem.• Skill: Construction of Gersmehl diagrams to show the inter-relationshipsbetween nutrient stores and flows between taiga, desert and tropicalrainforest.Skill: Analysis of data showing primary succession.• Skill: Investigation into the effect of an environmental disturbance on anecosystem.Understandings:• Introduced alien species can escape into local ecosystems and becomeinvasive.• Competitive exclusion and the absence of predators can lead to reduction inthe numbers of endemic species when alien species become invasive.• Pollutants become concentrated in the tissues of organisms at higher trophiclevels by biomagnification.• Macroplastic and microplastic debris has accumulated in marineenvironments.Applications and skills:• Application: Study of the introduction of cane toads in Australia and oneother local example of the introduction of an alien species.• Application: Discussion of the trade-off between control of the malarialparasite and DDT pollution.• Application: Case study of the impact of marine plastic debris on Laysanalbatrosses and one other named species.• Skill: Analysis of data illustrating the causes and consequences ofbiomagnification.• Skill: Evaluation of eradication programmes and biological control asmeasures to reduce the impact of alien speciesUnderstandings:• An indicator species is an organism used to assess a specific environmentalcondition.• Relative numbers of indicator species can be used to calculate the value of abiotic index.• In situ conservation may require active management of nature reserves ornational parks.• Ex situ conservation is the preservation of species outside their natural habitats.• Biogeographic factors affect species diversity.• Richness and evenness are components of biodiversity.Applications and skills:• Application: Case study of the captive breeding and reintroduction of anendangered animal species.• Application: Analysis of the impact of biogeographic factors on diversitylimited to island size and edge effects.• Skill: Analysis of the biodiversity of two local communities using Simpson’sreciprocal index of diversity.Understandings:• Sampling techniques are used to estimate population size.• The exponential growth pattern occurs in an ideal, unlimited environment.• Population growth slows as a population reaches the carrying capacity of theenvironment.• The phases shown in the sigmoid curve can be explained by relative rates ofnatality, mortality, immigration and emigration.• Limiting factors can be top down or bottom up.Applications and skills:• Application: Evaluating the methods used to estimate the size of commercialstock of marine resources.• Application: Use of the capture-mark-release-recapture method to estimatethe population size of an animal species.• Application: Discussion of the effect of natality, mortality, immigration andemigration on population size.Application: Analysis of the effect of population size, age and reproductivestatus on sustainable fishing practices.• Application: Bottom-up control of algal blooms by shortage of nutrients andtop-down control by herbivory.• Skill: Modelling the growth curve using a simple organism such as yeast orspecies of LemnaUnderstandings:• Nitrogen-fixing bacteria convert atmospheric nitrogen to ammonia.• Rhizobium associates with roots in a mutualistic relationship.• In the absence of oxygen denitrifying bacteria reduce nitrate in the soil.• Phosphorus can be added to the phosphorus cycle by application of fertilizeror removed by the harvesting of agricultural crops.• The rate of turnover in the phosphorus cycle is much lower than the nitrogencycle.• Availability of phosphate may become limiting to agriculture in the future.• Leaching of mineral nutrients from agricultural land into rivers causeseutrophication and leads to increased biochemical oxygen demand.Applications and skills:• Application: The impact of waterlogging on the nitrogen cycle.• Application: Insectivorous plants as an adaptation for low nitrogenavailability in waterlogged soils.• Skill: Drawing and labelling a diagram of the nitrogen cycle.• Skill: Assess the nutrient content of a soil sample

• Define species and list their characteristics.

• Distinguish between the various modes of nutrition different species possess.

• Define a community and list its characteristics.

• Define a population and list its characteristics.

• Describe how light energy is converted into chemical energy.

• Outline why energy is lost from an ecosystem.

• Define trophic levels.

• Describe why energy is lost between trophic levels.

• Explain the greenhouse effect.

• Describe the greenhouse gases and their harmful effects on the environment.

• Describe why coral reefs are used as a barometer for the health of an aquatic ecosystem.

• Define biogeochemical cycles and locate the primary reservoirs of the chemicals in these cycles.

• Describe water cycle in detail.

• Define the terms aquifers and water table.

• Describe nitrogen cycle in detail.

• Define the terms of nitrogen-fixation, nitrification, de-nitrification and ammonification.

• Describe productivity in terms of gross primary productivity and net primary productivity.

• Explain the flow of energy in successive trophic levels.

• Interpret the pyramids of number, biomass and energy.

• Define ecological succession as the process through which ecosystems change from simple to complex.

• Describe primary and secondary succession.

• Differentiate between xerarch and hydrarch succession.

• Explain the xerarch succession on a bare rock starting from the small pockets of lichens to the vegetations of flowering plants.

• Describe characteristics of a population, such as growth, density, distribution, carrying capacity, minimum/viable size.

• Explain, using demographic principles, problems related to the rapid growth of human populations and the effects of that growth on future generations (e.g., relate the carrying capacity of the Earth to the growth of populations and their consumption of resources).

 

How do various components (living organisms, ecosystems etc) of an environemnt interact and depend on one another?

This chapter is important as it gives the student a solid undestanding of ecology.

 

Evolution

Understanding• Describe creationism and the theory of evolution as two contradictory ideas.• Relate Quranic injunctions to the process of the evolution of man.Understanding• Explain how biogeography provides an evidence for evolution.• Describe the evidences of evolution that come from paleontology, comparative anatomy and molecularbiology.• Differentiate between convergent and divergent evolution on the basis of inheritance of the homologousand analogous structures.Skills(Initiating and Planning)• Identify questions that arise from concepts of evolution and diversity (e.g., What factors have contributedto the dilemma that pharmaceutical companies face in trying to develop new antibiotics because somany micro-organisms are resistant to existing antibiotics?).(Analyzing and Interpreting)• Interpret different homologous and analogous structures through observation in plants.Understanding• Describe the theories that have been put forwarded about the mechanism of evolution of eukaryotesfrom prokaryotesUnderstanding• Justify Lamarck as an early proponent of evolution.• Describe the theory of inheritance of acquired characters, as proposed by Lamarck.• Outline the steps of the evolution of the giraffe, as illustrated in Lamarckism.• State the drawbacks in Lamarckism.Skills(Initiating and Planning)• Hypothesize whether Lamarck was criticized in his day for advocating the ideas of evolution or for themechanism he proposed.Understanding• Briefly describe the observations Darwin made during his voyage on HMS Beagle.• Explain the theory of natural selection as proposed by Darwin.• Describe the ideas of Charles Lyell, James Hutton and Thomas Malthus that contributed in the earlydevelopment of Darwinism.• Describe the role of Alfred Wallace in motivating Darwin to publish the theory of natural selection.• Justify, on the grounds that both Wallace’s and Darwin’s papers were published in the Journal of theproceedings of the Linnaean Society, why the theory was attributed to Darwin.Understanding• Describe the assumptions of the Hardy-Weinberg theorem and relate these to the factors that changethe allelic frequencies of the population.• Explain the concept of genetic drift (neutral selection).• Define the concept of speciation and explain the mechanisms of speciation (allopatric, parapatric andsympatric speciation).Skills(Analyzing and Interpreting)• Solve problems related to gene frequencies using the Hardy-Weinberg equation.Science Technology and Society Connections• List the vestigial structures found in man and categorize them in homologous or analogous structures.• Describe and analyze examples of technology that have extended or modified the scientificunderstanding of evolution (e.g., the contribution of radiometric dating to the palaeontological analysis offossils).

1 outline the theory of evolution as a process leading to theformation of new species from pre-existing species overtime, as a result of changes to gene pools from generation togeneration2 discuss how DNA sequence data can show evolutionaryrelationships between species3 explain how speciation may occur as a result of geneticisolation by:• geographical separation (allopatric speciation)• ecological and behavioural separation (sympatricspeciation)

Understandings:• Evolution occurs when heritable characteristics of a species change.• The fossil record provides evidence for evolution.• Selective breeding of domesticated animals shows that artificial selection cancause evolution.• Evolution of homologous structures by adaptive radiation explainssimilarities in structure when there are differences in function.• Populations of a species can gradually diverge into separate species byevolution.• Continuous variation across the geographical range of related populationsmatches the concept of gradual divergence.Applications and skills:• Application: Development of melanistic insects in polluted areas.• Application: Comparison of the pentadactyl limb of mammals, birds,amphibians and reptiles with different methods of locomotion.Understandings:• Natural selection can only occur if there is variation among members of thesame species.• Mutation, meiosis and sexual reproduction cause variation betweenindividuals in a species.• Adaptations are characteristics that make an individual suited to itsenvironment and way of life.• Species tend to produce more offspring than the environment can support.• Individuals that are better adapted tend to survive and produce moreoffspring while the less well adapted tend to die or produce fewer offspring.• Individuals that reproduce pass on characteristics to their offspring.• Natural selection increases the frequency of characteristics that makeindividuals better adapted and decreases the frequency of othercharacteristics leading to changes within the species.Applications and skills:• Application: Changes in beaks of finches on Daphne Major.• Application: Evolution of antibiotic resistance in bacteria.Understandings:• The binomial system of names for species is universal among biologists andhas been agreed and developed at a series of congresses.• When species are discovered they are given scientific names using thebinomial system.• Taxonomists classify species using a hierarchy of taxa.• All organisms are classified into three domains.• The principal taxa for classifying eukaryotes are kingdom, phylum, class,order, family, genus and species.• In a natural classification, the genus and accompanying higher taxa consist ofall the species that have evolved from one common ancestral species.• Taxonomists sometimes reclassify groups of species when new evidenceshows that a previous taxon contains species that have evolved fromdifferent ancestral species.• Natural classifications help in identification of species and allow theprediction of characteristics shared by species within a group.Applications and skills:• Application: Classification of one plant and one animal species from domainto species level.• Application: Recognition features of bryophyta, filicinophyta, coniferophytaand angiospermophytaApplication: Recognition features of porifera, cnidaria, platylhelmintha,annelida, mollusca, arthropoda and chordata.• Application: Recognition of features of birds, mammals, amphibians, reptilesand fish.• Skill: Construction of dichotomous keys for use in identifying specimens.Understandings:• A clade is a group of organisms that have evolved from a common ancestor.• Evidence for which species are part of a clade can be obtained from the basesequences of a gene or the corresponding amino acid sequence of a protein.• Sequence differences accumulate gradually so there is a positive correlationbetween the number of differences between two species and the time sincethey diverged from a common ancestor.• Traits can be analogous or homologous.• Cladograms are tree diagrams that show the most probable sequence ofdivergence in clades.• Evidence from cladistics has shown that classifications of some groups basedon structure did not correspond with the evolutionary origins of a group orspecies.Applications and skills:• Application: Cladograms including humans and other primates.• Application: Reclassification of the figwort family using evidence fromcladistics.• Skill: Analysis of cladograms to deduce evolutionary relationships.

• Describe creationism and the theory of evolution as two contradictory ideas.

• Explain how biogeography provides an evidence for evolution.

• Describe the evidences of evolution that come from paleontology, comparative anatomy and molecular biology.

• Differentiate between convergent and divergent evolution on the basis of inheritance of the homologous and analogous structures.

• Describe the theories that have been put forwarded about the mechanism of evolution of eukaryotes from prokaryotes

• Justify Lamarck as an early proponent of evolution.

• Describe the theory of inheritance of acquired characters, as proposed by Lamarck.

• Outline the steps of the evolution of the giraffe, as illustrated in Lamarckism.

• State the drawbacks in Lamarckism.

• Briefly describe the observations Darwin made during his voyage on HMS Beagle.

• Explain the theory of natural selection as proposed by Darwin.

• Describe the ideas of Charles Lyell, James Hutton and Thomas Malthus that contributed in the early development of Darwinism.

• Describe the role of Alfred Wallace in motivating Darwin to publish the theory of natural selection.

• Justify, on the grounds that both Wallace’s and Darwin’s papers were published in the Journal of the proceedings of the Linnaean Society, why the theory was attributed to Darwin.

• Describe the assumptions of the Hardy-Weinberg theorem and relate these to the factors that change the allelic frequencies of the population.

• Explain the concept of genetic drift (neutral selection).

• Define the concept of speciation and explain the mechanisms of speciation (allopatric, parapatric andsympatric speciation).

 

How does evolution occur in a particular direction? What factors affect the rate and direction of evolution? What pieces of evidence support the theory of evolution?

This chapter gives the student a solid understanding of the various theories and evidence for evolution.

 

Prokaryotes, Protists and Fungi

Understanding• Outline the taxonomic position of prokaryotes in terms of domains archaea and bacteria and in terms ofkingdom monera.• Explain the phylogenetic position of prokaryotes.Skills(Performing and Recording)• Identify bacteria from curd, mouth, or bacterial culture.Understanding• List the unifying archeal features that distinguish them from bacteria.• Explain that most Archaea inhabit extreme environments.Understanding• Justify the occurrence of bacteria in the widest range of habitats.• List the diagnostic features of the major groups of bacteria.• Justify why cyanobacteria are considered as the most prominent of the photosynthetic bacteriaSkills(Performing and Recording)• Identify the characteristics of Nostoc, Ocillatoria and Anabaena through observation from fresh orpreserved material.Understanding• Describe detailed structure and chemical composition of bacterial cell wall and other coverings.• Compare cell wall differences in Gram-positive and Gram-negative bacteria.• Explain the great diversity of shapes and sizes found in bacteria.• Justify the endospore formation in bacteria to withstand unfavorable conditions.• Explain motility in bacteria.• Describe structure of bacterial flagellum.• Describe genomic organization of bacteria.Skills(Performing and Recording)• Stain bacteria using Grams staining technique.• Observe bacterial culture for different shapes and sizes.Understanding• Classify bacteria on the basis of methods of obtaining energy and carbon.• Describe autotrophic and heterotrophic nutrition in bacteria.• Explain the pigment composition in cyanobacteria.• Differentiate between the photosynthesis mechanisms in cyanobacteria and other photosyntheticbacteria.Skills(Performing and Recording)• Prepare and observe temporary mount of root nodule bacteria.Understanding• List the phases in the growth of bacteria.• Describe different methods of reproduction in bacteria.• Explain how mutations and genetic recombinations lend variability to bacterial reproduction.Skills(Interpreting and Communication)• Draw a graph to present the time taken in each phase of bacterial growth and the number of bacteria.Understanding• Describe bacteria as recyclers of nature.Outline the ecological and economic importance of bacteria.• Explain the use of bacteria in research and technology.• Describe important bacterial diseases in man e.g. cholera, typhoid, tuberculosis, and pneumonia;emphasizing their symptoms, causative bacteria, treatments, and preventative measures.• Describe important bacterial diseases in plants in terms of spots, blights, soft rots, wilts, and galls;emphasizing their symptoms, causative bacteria, and preventative measures.Understanding• Define the term normal flora.• List the important bacteria that make the normal bacterial flora residing in the oral cavity, respiratory andurinogenital tracts and large intestine of man.• Describe the benefits of the bacterial flora of humans.Understanding• List the chemical and physical methods used to control harmful bacteria.Skills(Initiating and Planning)• Acquire some basic microbiological and safety techniques.Science Technology and Society Connections• Relate the causes of food poisoning and the sanitation conditions in restaurants.• Justify why it is important to disinfect articles of food and utensils before use.• Narrate how bacterial diseases have affected human societies in the past.• Suggest how we can stop any epidemic to occur in future.• List some biotechnologies utilizing bacteria.Understanding• Explain protists as a diverse group of eukaryotes that has polyphyletic origin and defined only byexclusion from other groups.Understanding• Describe the salient features with examples of protozoa, algae, myxomycota and oomycota as the majorgroups of protists.• Justify how protists are important for humans.Skills(Performing and Recording)• Observe and draw representative members of each group of protists.Understanding• List the characteristics that distinguish fungi from other groups and give reasons why fungi are classifiedin a separate kingdom.Understanding• Classify fungi into zygomycota, ascomycota and basidiomycota and give the diagnostic features of eachgroup.Skills(Performing and Recording)• Observe black bread mold and Penicillium from fresh culture and prepared slides and draw labeleddiagrams of their life cyclesUnderstanding• Explain yeast as unicellular fungi that are used for baking and brewing and are also becoming veryimportant for genetic research.• Name a few fungi from which antibiotics are obtained.• Explain the mutualism established in mycorrhizae and lichen associations.• Give examples of edible fungi.• Describe the ecological impact of fungi causing decomposition and recycling of materials.• Explain the pathogenic role of fungi.Science Technology and Society Connections• Explain what clues protists provide with respect to the evolution of the other three kingdoms ofeukaryotes.• Describe how helpful fungi have been for us as source of antibiotics and other useful chemicals

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• Outline the taxonomic position of prokaryotes in terms of domains archaea and bacteria and in terms of kingdom monera.

• Explain the phylogenetic position of prokaryotes.

• Justify the occurrence of bacteria in the widest range of habitats.

• List the diagnostic features of the major groups of bacteria.

• Justify why cyanobacteria are considered as the most prominent of the photosynthetic bacteria

• Describe detailed structure and chemical composition of bacterial cell wall and other coverings.

• Compare cell wall differences in Gram-positive and Gram-negative bacteria.

• Explain the great diversity of shapes and sizes found in bacteria.

• Justify the endospore formation in bacteria to withstand unfavorable conditions.

• Explain motility in bacteria.

• Describe structure of bacterial flagellum.

• Describe genomic organization of bacteria.

• Classify bacteria on the basis of methods of obtaining energy and carbon.

• Describe autotrophic and heterotrophic nutrition in bacteria.

• Explain the pigment composition in cyanobacteria.

• Differentiate between the photosynthesis mechanisms in cyanobacteria and other photosynthetic bacteria.

• List the phases in the growth of bacteria.

• Describe different methods of reproduction in bacteria.

• Explain how mutations and genetic recombinations lend variability to bacterial reproduction.

• Describe bacteria as recyclers of nature.Outline the ecological and economic importance of bacteria.

• Explain the use of bacteria in research and technology.

• Describe important bacterial diseases in man e.g. cholera, typhoid, tuberculosis, and pneumonia; emphasizing their symptoms, causative bacteria, treatments, and preventative measures.

• Describe important bacterial diseases in plants in terms of spots, blights, soft rots, wilts, and galls; emphasizing their symptoms, causative bacteria, and preventative measures.

• Define the term normal flora.

• List the important bacteria that make the normal bacterial flora residing in the oral cavity, respiratory andurinogenital tracts and large intestine of man.

• Describe the benefits of the bacterial flora of humans.

• List the chemical and physical methods used to control harmful bacteria.

• Explain protists as a diverse group of eukaryotes that has polyphyletic origin and defined only byexclusion from other groups.

• Describe the salient features with examples of protozoa, algae, myxomycota and oomycota as the majorgroups of protists.

• Justify how protists are important for humans.

• Classify fungi into zygomycota, ascomycota and basidiomycota and give the diagnostic features of eachgroup.

• Explain yeast as unicellular fungi that are used for baking and brewing and are also becoming veryimportant for genetic research.

• Name a few fungi from which antibiotics are obtained.

• Explain the mutualism established in mycorrhizae and lichen associations.

• Give examples of edible fungi.

• Describe the ecological impact of fungi causing decomposition and recycling of materials.

• Explain the pathogenic role of fungi.

 

What unique characteristics of prokaryotes, protists and fungi biology enable them to thrive in their environments?

Students must learn the unique charactersistics of prokaryotes, protists and fungi biology and how they differ from mammalian/human biology due to their unique environements and behaviours..

 

Acellular life

Understanding• Justify the status of viruses among living and non-living things.• Trace the history of viruses since their discovery.• Classify viruses on the bases of their hosts and structure.• Explain the structure of a model bacteriophage, flu virus and HIV.Skills(Interpreting and Recording)• Make a list of names of at least five viruses each in plants and animals that have DNA or RNA.• Draw labeled diagrams of bacteriophage, flu virus and HIV.Understanding• Justify why a virus must have a host cell to parasitize in order to complete its life cycle.• Explain how a virus survives inside a host cell, protected from the immune system.• Determine the method a virus employs to survive/ pass over unfavorable conditions when it does nothave a host to complete the life cycle.Skills(Interpreting and Recording)• Record the symptoms of flu in any individual.• Make a list of names of at least five viruses each in plants and animals that are specific for a specifichost.Understanding• Describe the Lytic and Lysogenic life cycles of a virus.• Outline the usage of bacteriophage in genetic engineering.Skills(Interpreting and Recording)• Make a list of the sequences involved in the lytic life cycle of a bacteriophage.Understanding• Explain the life cycle of HIV.• Justify the name of the virus i.e., “Human Immunodeficiency Virus” by establishing T-helper cells asthe basis of immune system.• Reason out the specificity of HIV on its host cells.• List the symptoms of AIDS.• Explain opportunistic diseases that may attack an AIDS victim.• Describe the treatments available for AIDS.• List some common control measures against the transmission of HIV.Skills(Interpreting and Recording)• Predict from the given data the incidence and prevalence of AIDS over a period of next five years.• List the factors responsible for the spread of this disease.Understanding• Describe the causative agent, symptoms, treatment and prevention of the following viral diseases:hepatitis, herpes, polio and leaf curl virus disease of cotton.• List the sources of transmission for each of the above-mentioned diseases.• Assess from the given data the economic loss from viral infections (cotton leaf curl virus disease andbird flu virus) in Pakistan.Skills(Interpreting and Communicating)• Compare from the data given in the book, the number of fatalities caused by hepatitis, herpes andpolio combined with the total fatalities caused by AIDS.• Give reasons in favor of the statement “Prevention is better than cure” and present the arguments inthe class.Understanding• Describe the structure of prions and viroids.• List the diseases caused by prions and viroids.TS Connections• Interpret how viral infections cause global economic loss.• Justify how the invention of electron microscope revolutionized the science of microscopic organisms.• Suggest ways to rid human civilization of viruses.• Correlate the social and cultural values of a country with the prevalence of AIDS.• Describe the limitations of the vaccine for the common cold / flu virus

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• Justify the status of viruses among living and non-living things.

• Trace the history of viruses since their discovery.

• Classify viruses on the bases of their hosts and structure.

• Explain the structure of a model bacteriophage, flu virus and HIV.

• Justify why a virus must have a host cell to parasitize in order to complete its life cycle.

• Explain how a virus survives inside a host cell, protected from the immune system.

• Determine the method a virus employs to survive/ pass over unfavorable conditions when it does nothave a host to complete the life cycle.

• Describe the Lytic and Lysogenic life cycles of a virus.

• Outline the usage of bacteriophage in genetic engineering.

• Explain the life cycle of HIV.

• Justify the name of the virus i.e., “Human Immunodeficiency Virus” by establishing T-helper cells asthe basis of immune system.

• Reason out the specificity of HIV on its host cells.

• List the symptoms of AIDS.

• Explain opportunistic diseases that may attack an AIDS victim.

• Describe the treatments available for AIDS.

• List some common control measures against the transmission of HIV.

• Describe the causative agent, symptoms, treatment and prevention of the following viral diseases:hepatitis, herpes, polio and leaf curl virus disease of cotton.

• List the sources of transmission for each of the above-mentioned diseases.

• Describe the structure of prions and viroids.

• List the diseases caused by prions and viroids.TS Connections

• Interpret how viral infections cause global economic loss.

• Justify how the invention of electron microscope revolutionized the science of microscopic organisms.

• Suggest ways to rid human civilization of viruses.

• Correlate the social and cultural values of a country with the prevalence of AIDS.

• Describe the limitations of the vaccine for the common cold / flu virus

 

What unique characteristics of virus biology enable them to thrive in their environments?

Students must learn the unique charactersistics of acellular lifei biology and how they differ from mammalian/human biology due to their unique environements and behaviours..

 

Plants

Understanding• List the macro and micronutrients of plants highlighting the role of each nutrient.• State the examples of carnivorous plant.Understanding• Explain the role of stomata and palisade tissue in the exchange of gases in plants.• Relate transpiration with gas exchange in plants.Skills(Performing and Recording)• Perform to demonstrate with the help of indicator (hydrogen carbonate) evolution of CO 2 from leaf discsplaced in dark and light.Understanding• Describe the structure of xylem vessel elements, sieve tube elements, companion cells, trachieds andrelate their structures with functions.• Explain the movement of water between plant cells, and between the cells and their environment interms of water potential.• Explain the movement of water through roots in terms of symplast, apoplast and vacuolar pathways.• Explain the movement of water in xylem through TACT mechanism.• Describe the mechanisms involved in the opening and closing of stomata.• Explain the movement of sugars within plants.Skills(Performing and Recording)• Identify vessel elements and phloem sieve tubes from the microscopic slides of LS of a dicot stem.• Illustrate diagrammatically the pathway of water in root, stem and leaf.Understanding• Define osmotic adjustment.• Explain movement of water into or out of cell in isotonic, hypotonic, and hypertonic conditions.• Describe osmotic adjustments in hydrophytic (marine and freshwater), xerophytic and mesophyticplants.• Explain the osmotic adjustments of plants in saline soils.• List the adaptations in plants to cope with low and high temperatures.Skills(Interpreting and Analyzing)• Interpret the adaptive differences through survey of xerophytic, mesophytic and hydrophytic plants.• Illustrate the structure and position of stomata in xerophytic, mesophytic and hydrophytic plants.Understanding• Explain the turgor pressure and explain its significance in providing support to herbaceous plants.• Describe the structure of supporting tissues in plants.Understanding• Define growth and explain primary and secondary growth in plants.• Describe the role of apical meristem and lateral meristem in primary and secondary growth.• Explain how annual rings are formed.• Explain influence of apical meristem on the growth of lateral shoots.Skills(Performing and Recording)• Locate annual rings in the log of a tree.• Calculate the age of a plant by counting number of annual rings.Understanding• Explain the role of important plant growth regulators.• Explain the types of movement in plants in response to light, force of gravity, touch and chemicals.• Define photoperiodism.• Classify plants on the basis of photoperiodism and give examples.Describe the mechanism of photoperiodism with reference to the mode of action of phytochrome.• Explain the role of low temperature treatment on flower production especially to biennials andperennials.Skills(Performing and Recording)• Demonstrate through simple experiments the phototropism, geotropism and thigmotropism in plants.• Demonstrate folding of Mimmosa leaf after touch.Science Technology and Society Connections• Identify some major symptoms of mineral deficiencies in plants e.g. necrosis, chlorosis, stunted growthetc.• Correlate climatic record with tree growth.• Describe the reasons for bushy and cylindrical growth

1 draw plan diagrams of transverse sections of stems, rootsand leaves of herbaceous dicotyledonous plants frommicroscope slides and photomicrographs2 describe the distribution of xylem and phloem in transversesections of stems, roots and leaves of herbaceousdicotyledonous plants3 draw and label xylem vessel elements, phloem sieve tubeelements and companion cells from microscope slides,photomicrographs and electron micrographs4 relate the structure of xylem vessel elements, phloem sievetube elements and companion cells to their functions1 state that some mineral ions and organic compounds can betransported within plants dissolved in water2 describe the transport of water from the soil to the xylemthrough the:• apoplast pathway, including reference to lignin andcellulose• symplast pathway, including reference to the endodermis,Casparian strip and suberin3 explain that transpiration involves the evaporation of waterfrom the internal surfaces of leaves followed by diffusion ofwater vapour to the atmosphere4 explain how hydrogen bonding of water molecules is involvedwith movement of water in the xylem by cohesion-tension intranspiration pull and by adhesion to cellulose in cell walls5 make annotated drawings of transverse sections of leavesfrom xerophytic plants to explain how they are adapted toreduce water loss by transpiration6 state that assimilates dissolved in water, such as sucrose andamino acids, move from sources to sinks in phloem sievetubes7 explain how companion cells transfer assimilates tophloem sieve tubes, with reference to proton pumps andcotransporter proteins8 explain mass flow in phloem sieve tubes down a hydrostaticpressure gradient from source to sink

1 explain that stomata respond to changes in environmentalconditions by opening and closing and that regulation ofstomatal aperture balances the need for carbon dioxideuptake by diffusion with the need to minimise water loss bytranspiration2 explain that stomata have daily rhythms of opening andclosing3 describe the structure and function of guard cells and explainthe mechanism by which they open and close stomata4 describe the role of abscisic acid in the closure of stomataduring times of water stress, including the role of calcium ionsas a second messenger

Understandings:• Transpiration is the inevitable consequence of gas exchange in the leaf.• Plants transport water from the roots to the leaves to replace losses fromtranspiration.• The cohesive property of water and the structure of the xylem vessels allowtransport under tension.• The adhesive property of water and evaporation generate tension forces inleaf cell walls.• Active uptake of mineral ions in the roots causes absorption of water by osmosis.Applications and skills:• Application: Adaptations of plants in deserts and in saline soils for waterconservation.• Application: Models of water transport in xylem using simple apparatusincluding blotting or filter paper, porous pots and capillary tubing.• Skill: Drawing the structure of primary xylem vessels in sections of stemsbased on microscope images.• Skill: Measurement of transpiration rates using potometers. (Practical 7)• Skill: Design of an experiment to test hypotheses about the effect oftemperature or humidity on transpiration rates.Understandings:• Plants transport organic compounds from sources to sinks.• Incompressibility of water allows transport along hydrostatic pressuregradients.• Active transport is used to load organic compounds into phloem sieve tubesat the source.• High concentrations of solutes in the phloem at the source lead to wateruptake by osmosis.• Raised hydrostatic pressure causes the contents of the phloem to flowtowards sinks.Applications and skills:• Application: Structure–function relationships of phloem sieve tubes.• Skill: Identification of xylem and phloem in microscope images of stem androot.• Skill: Analysis of data from experiments measuring phloem transport ratesusing aphid stylets and radioactively-labelled carbon dioxide.Understandings:• Undifferentiated cells in the meristems of plants allow indeterminate growth.• Mitosis and cell division in the shoot apex provide cells needed for extensionof the stem and development of leaves.• Plant hormones control growth in the shoot apex.• Plant shoots respond to the environment by tropisms.• Auxin efflux pumps can set up concentration gradients of auxin in planttissue.• Auxin influences cell growth rates by changing the pattern of geneexpression.Applications and skills:• Application: Micropropagation of plants using tissue from the shoot apex,nutrient agar gels and growth hormones.• Application: Use of micropropagation for rapid bulking up of new varieties,production of virus-free strains of existing varieties and propagation oforchids and other rare speciesUnderstandings:• Flowering involves a change in gene expression in the shoot apex.• The switch to flowering is a response to the length of light and dark periodsin many plants.• Success in plant reproduction depends on pollination, fertilization and seeddispersal.• Most flowering plants use mutualistic relationships with pollinators in sexualreproduction.Applications and skills:• Application: Methods used to induce short-day plants to flower out of season.• Skill: Drawing internal structure of seeds.• Skill: Drawing of half-views of animal-pollinated flowers.• Skill: Design of experiments to test hypotheses about factors affectinggermination.

• List the macro and micronutrients of plants highlighting the role of each nutrient.

• State the examples of carnivorous plant.Understanding

• Explain the role of stomata and palisade tissue in the exchange of gases in plants.

• Relate transpiration with gas exchange in plants.

• Describe the structure of xylem vessel elements, sieve tube elements, companion cells, trachieds andrelate their structures with functions.

• Explain the movement of water between plant cells, and between the cells and their environment interms of water potential.

• Explain the movement of water through roots in terms of symplast, apoplast and vacuolar pathways.

• Explain the movement of water in xylem through TACT mechanism.• Describe the mechanisms involved in the opening and closing of stomata.

• Explain the movement of sugars within plants.

• Define osmotic adjustment.

• Explain movement of water into or out of cell in isotonic, hypotonic, and hypertonic conditions.

• Describe osmotic adjustments in hydrophytic (marine and freshwater), xerophytic and mesophytic plants.

• Explain the osmotic adjustments of plants in saline soils.

• List the adaptations in plants to cope with low and high temperatures.• Explain the turgor pressure and explain its significance in providing support to herbaceous plants.

• Describe the structure of supporting tissues in plants.

• Define growth and explain primary and secondary growth in plants.

• Describe the role of apical meristem and lateral meristem in primary and secondary growth.

• Explain how annual rings are formed.• Explain influence of apical meristem on the growth of lateral shoots.

• Explain the role of important plant growth regulators.

• Explain the types of movement in plants in response to light, force of gravity, touch and chemicals.

• Define photoperiodism.

• Classify plants on the basis of photoperiodism and give examples.Describe the mechanism of photoperiodism with reference to the mode of action of phytochrome.

• Explain the role of low temperature treatment on flower production especially to biennials andperennials.

 

What unique characteristics of plant biology enable them to thrive in their environments?

Students must learn the unique charactersistics of plant biology and how they differ from mammalian/human biology due to their unique environements and behaviours..

 

Human Physiology

Understanding• Describe the mechanical and chemical digestion in oral cavity.• Explain swallowing and peristalsis.• Describe the structure of stomach and relate each component with the mechanical and chemicaldigestion in stomach.• Explain the role of nervous system and gastrin hormone on the secretion of gastric juice.• Describe the major actions carried out on food in the three regions of the small intestine.• Explain the absorption of digested products from the small intestine lumen to the blood capillaries andlacteals of the villi.• Describe the component parts of large intestine with their respective roles.• Correlate the involuntary reflex for egestion in infants and the voluntary control in adults.Skills(Analyzing, Interpreting and Communication)• List structural features that increase surface area of small intestine.• Identify the components of villi by observing the transverse section of intestine under microscope.Understanding• Explain the storage and metabolic role of liver.• Describe composition of bile and relate the constituents with respective roles.• Outline the structure of pancreas and explain its function as an exocrine gland.• Relate the secretion of bile and pancreatic juice with the secretin hormone.Skills(Analyzing and Interpreting)• Identify and draw the sections of liver and pancreas from prepared slides.- Disorders related to Digestive System and Food HabitsUnderstanding• Describe the causes, prevention, and treatment of the following disorders; ulcer, food poisoning,dyspepsia.• Describe obesity in terms of its causes, preventions and related disorders.• Explain the symptoms and treatments of bulimia nervosa and anorexia nervosa.Science Technology and Society Connections• Relate hepatitis and jaundice with the functions of liver.• Relate ulcer, food poisoning and dyspepsia with the eating habits of the societyUnderstanding• State the location of heart in the body and define the role of pericardium.• Describe the structure of the walls of heart and rationalize the thickness of the walls of each chamber.• Describe the flow of blood through heart as regulated by the valves.• State the phases of heartbeat.• Explain the role of SA node, AV node and Purkinji fibers in controlling the heartbeat.• List the principles and uses of Electrocardiogram.Skills(Analyzing, Interpreting and Communication)• Correlate the lub-dub sounds of the closing of heart valves with the monitoring of the heartbeat.• Identify the phases of heartbeat on a printed ECG.• Compare the ECG of a cardiac patient with that of a healthy man.(Performing and Recording)• Dissect the heart of sheep / goat and describe its internal structure.Understanding• Describe the detailed structure of arteries, veins and capillaries.• Describe the role of arterioles in vasoconstriction and vasodilation.• Describe the role of precapillary sphincters in regulating the flow of blood through capillaries.• Trace the path of the blood through the pulmonary and systemic circulation (coronary, hepatic-portaland renal circulation).• Compare the rate of blood flow through arteries, arterioles, capillaries, venules and veins.Skills(Analyzing and Interpreting)• Differentiate between an artery and a vein by observing prepared slides.• Justify how vasoconstriction or vasodilation is reflective of emotions.Understanding• Define blood pressure and explain its periods of systolic and diastolic pressure.• State the role of baroreceptors and volume receptors in regulating the blood pressure.Skills(Performing and Recording)• Measure blood pressure by using sphygmomanometer.Understanding• Define the term thrombus and differentiate between thrombus and embolus.• Identify the factors causing atherosclerosis and arteriosclerosis.• Categorize Angina pectoris, heart attack, and heart failure as the stages of cardiovascular diseasedevelopment.• State the congenital heart problem related to the malfunctioning of cardiac valves.• Describe the principles of angiography.• Outline the main principles of coronary bypass, angioplasty and open-heart surgery.• Define hypertension and describe the factors that regulate blood pressure and can lead to hypertensionand hypotension.• List the changes in life styles that can protect man from hypertension and cardiac problems.Understanding• Describe the formation, composition and function of intercellular fluid.• Compare the composition of intercellular fluid with that of lymph.• State the structure and role of lymph capillaries, lymph vessels and lymph trunks.• Describe the role of lymph vessels (lacteals) present in villi.• Describe the functions of lymph nodes and state the role of spleen as containing lymphoid tissue.Skills(Initiating and Planning)• Justify in what way the blood circulatory system is dependent on the lymphatic system.• Interpret why the swelling of the lymph nodes is a cause of concern.(Analyzing and Interpreting)• Trace the path of lymph from a lymph capillary until it is returned to the blood.STS Connections• Rationalize the use of artificial pacemaker in patients of cardiac arrhythmias.• Hypothesize the role and effects of diuretic drugs in regulating blood pressure.• List major hospitals of cardiology working in his/her province.• List the advantages and disadvantages of coronary bypass surgery

Understanding• Define the respiratory surface and list its properties• Describe the main structural features and functions of the components of human respiratory system.• Describe the ventilation mechanism in humans.• State lung volumes and capacities.• Explain how breathing is controlled.Skills(Analyzing and Interpreting)• Draw and label a diagram to illustrate the microscopic structure of human lung with the help of slides.• Trace the path of air through different parts of human respiratory system.(Analyzing and Interpreting)• Identify different parts of the respiratory system of a dissected frog (dissection would be done by theteacher).• Examine some sheep lungs obtained from butchers’ shop.Understanding• Describe the transport of oxygen and carbon dioxide through blood.• Describe the role of respiratory pigments.Understanding• State the causes, symptoms and treatment of upper Respiratory Tract Infections (sinusitis, otitis media)and lower Respiratory Tract Infections (pneumonia, pulmonary tuberculosis).• Describe the disorders of lungs (emphysema and lung cancer).• List the effects of smoking on respiratory systemSkills(Analyzing and Interpreting)• Compare and interpret the X-ray films of lungs of a smoker with that of a healthy man.Science Technology and Society Connections• Describe the development and working of artificial breathing apparatus (for use under water and at highaltitude and by firemen).• Justify why birds perform much better than man at high altitude.• Describe the purpose of Mouth to Mouth method for artificial respiration in First Aid.• Relate the transportation of gases to hiccups, sneezing and snoring.• Describe the carbon monoxide poisoning (caused by gas heaters left on overnight in closedenvironments).Understanding• Describe three elements i.e. receptors, control center and effectors which operate homeostaticmechanisms.• Relate the homeostatic mechanisms with the negative and positive feedback systems.Skills(Initiating and Planning)• Investigate why positive feedback mechanisms in humans are sometimes associated with severe healthproblems.• List some of the behavioral responses of the animals to maintain homeostasis.(Interpreting and Communicating)• Draw a flow chart to show negative feedback of homeostatic mechanisms by taking an example ofhormone.Understanding• Differentiate between osmoconformers and osmoregulators.• Define osmoregulation.• Explain the problems faced by osmoregulators.• Explain the different methods of osmoregulation found in freshwater, marine water and terrestrialhabitats.Understanding• List various nitrogenous compounds excreted during the process of excretion.• Explain the nature of excretory products in relation to habitat.Understanding• Explain different organs of urinary system. Describe the structure of kidney and relate it with its function.• Explain the detailed structure of nephron.• Explain the processes of glomerular filtration, selective re-absorption and tubular secretion as the eventsin kidney functioning.• Explain that concentration of urine is regulated by counter-current and hormonal mechanisms.• Justify the functioning of kidneys as both excretion and osmoregulation.• Compare the function of two major capillary beds in kidneys i.e. glomerular capillaries and peritubularcapillaries.Understanding• List urinary tract infections and the bacteria responsible.• Explain the causes and treatments of kidney stones.• Outline the causes of kidney failure.• Explain in detail the mechanism and problems related to dialysis.• Describe the principles and the problems associated with kidney transplant.Skills(Initiating and Planning)• Hypothesize kidney stone by studying the urine test of relevant patients.Understanding• Define theremoregulation and explain its needs.• Classify animals on the basis of the source of body’s heat i.e. ectotherms and endotherms.• Classify the animals on the bases of the ability to thermoregulate i.e. poikilotherms and homeotherms.• Describe the regulatory strategies in man for thermoregulation.Science Technology and Society Connections• Describe the importance of kidney donation for the benefit of kidney failure patients.• Name the important kidney transplant centers in his / her province.Understanding• Describe the structure of bone and compare it with that of cartilage.• Explain the functions of osteoblasts, osteoclasts and osteocytes.• Identify the main divisions of human skeleton.• List the bones of appendicular and axial skeleton of man.• Describe three types of joints i.e. fibrous joints, cartilaginous joints and synovial joints and give exampleof each.Skills(Initiating and Planning)• Relate the bipedal posture of man with his skeleton and musculature.(Analyzing and Interpreting)• Identify the bones of the pelvic girdles, pectoral girdle, arms and legs by using the model of humanskeleton.Understanding• Describe the disorders of human skeleton (disc-slip, spondylosis, sciatica, arthritis) and their causes.• State different types of fractures (simple, compound and complicated) and describe the repair processof simple fractures.• Describe the injuries in joints (dislocation and sprain) and their first aid treatment.• Describe the first-aid treatment for fracture.3- MusclesUnderstanding• Compare smooth muscles, cardiac muscles and skeletal muscles.• Explain the ultra-structure of the skeletal muscle.• Explain the sliding filaments model of muscle contraction.• Describe the action of antagonistic muscles in the movement of knee joint.Explain muscle fatigue, cramps and tetany.• Differentiate between tetanus and muscle tetany.Skills(Analyzing and Interpreting)• Compare the structure of skeletal, smooth and cardiac muscles with the help of prepared slides• Draw a diagram of sarcomere and label its parts.• Justify how the main functions of the skeleton are to act as a system of rods and levers, which aremoved by the muscles.• Justify why do the muscles pull but do not push.Science Technology and Society Connections• Name the techniques for joint transplantation.• Justify why the use of calcium in teenage and twenties can be a preventive action against osteoporosis.• Reason out the rigor mortis.• Relate improper posture to bone/joint problems.

Understanding• Describe the structures of male reproductive system identifying their functions.• Explain the principal reproductive hormones of human male and explain their role in the maintenanceand functioning of reproductive system.• Explain the structures of female reproductive system and describe their functions.• Describe the menstrual cycle emphasizing the role of hormones.Skills(Initiating and Planning)• Examine the prepared slides of histology of ovaries and draw its microscopic structures.• Expose the reproductive system of a dissected frog (dissection would be done by the teacher).Understanding• Describe the causes of female and male infertility.• Explain that in-vitro fertilization (test tube babies) is one of the methods to solve the problem of infertility.• Define miscarriage and state its causes.• Relate miscarriage with abortion.Understanding• Describe the causes, symptoms and treatment of gonorrhea and syphilis.• Explain AIDS as a worldwide sexually transmitted disease.Conceptual Linkages:STS Connections• Realize the affect of endocrine disrupting contaminants on the reproductive abilities.• Become aware of the ethical implications of abortion.• List the measures that can help to prevent transmission of HIV.Understanding• Describe cleavage and relate it with amount of yolk.• Explain the events of gastrulation.• List the tissues and organs formed from the three germ layers.• State the events of neurulation.• Describe the formation of neural crest and list the structures that are derived from neural crest cells.• Define organogenesis.Skills(Analyzing and Interpreting)• Identify the group of vertebrates, through diagrams of different blastula.• Identify the different stages in chick development through observation of prepared slides.Understanding• Through experimental narration, describe the role of the nucleus and cytoplasm in controllingdevelopment.• Give a brief overview of the work done by Hans Spemann in the discovery of induction.• Define organizers and differentiate between primary and secondary induction.Understanding• Describe the events of development in human in terms of first, second and third trimesters.• Describe in brief the development of twins and quadruplets.• Describe the structural details of placenta and umbilical cord.• Differentiate the terms gestation and pregnancy.Skills(Initiating and Planning)• Explain why proper nourishment of the mother is imperative during the third trimester of pregnancy.(Communication)• Draw a table to list the events of human development in the first trimester (first, second and thirdmonth), second trimester and third trimester.Understanding• Describe the role of fetal and maternal hormones in initiating labor pains and culminating in the birth ofbaby.• Define the term premature birth and correlate it with the growth phases in the second and thirdtrimesters.• Define afterbirth and describe how umbilical cord is detached from the baby.• Define colostrum and describe the role of prolactin in the production and of oxytocin in the secretion ofmilk.• State the hormonal regulation in the end of milk production.• Compare breast-feeding and bottle-feeding, in terms of advantages and disadvantages.Skills(Initiating and Planning)• When oxytocin is involved in the secretion of milk, hypothesize why new mothers often experiencecramps in uterus while nursing.Understanding• Describe the maternal derived abnormalities (rubella, abnormal neural tube, thyroid gland and limbdevelopment).• Relate the major genetic abnormalities in embryos with spontaneous abortion.• Describe how fetal surgery helps to correct the detected fetal developmental problems.5- Postnatal DevelopmentUnderstanding• Define the term allometric growth and correlate it with the postnatal development in human.Skills(Analyzing and Interpreting)• Using the knowledge about the postnatal growth rates of brain and jaws; interpret why a six-month oldbaby has the same jaw-skull proportions as it had at the time of birthUnderstanding• Define the term aging.• Rationalize aging as a part of normal development.• List the genetic and extrinsic factors responsible for aging.• State the changes (graying, thinning hair, pigmented patches of skin, slowed movements, fading vision,impaired hearing, reduced ability to adapt to stress and decreased resistance to infections) as primaryaging.• State the changes that are the result of environmental, lifestyle factors such as disease, disuse (lack ofexercise), and abuse (smoking, obesity, malnutrition, and exposure to ultra-violet light) as secondaryaging.• List some changes that occur at the system and those that occur at cellular level during aging.Science Technology and Society Connections• Describe how a blastula is divided into two (by using micromanipulator) to produce twins of animals forbiological research.• Rationalize that nursing is an important bonding time between mother and child, as it provides the childwith protection by mother’s immune system while its own develops.• List some of the diseases due to aging and what medical science is doing to treat those diseases.

1 state that the mammalian circulatory system is a closeddouble circulation consisting of a heart, blood and bloodvessels including arteries, arterioles, capillaries, venules andveins2 describe the functions of the main blood vessels of thepulmonary and systemic circulations, limited to pulmonaryartery, pulmonary vein, aorta and vena cava3 recognise arteries, veins and capillaries from microscopeslides, photomicrographs and electron micrographs andmake plan diagrams showing the structure of arteries andveins in transverse section (TS) and longitudinal section (LS)4 explain how the structure of muscular arteries, elastic arteries,veins and capillaries are each related to their functions5 recognise and draw red blood cells, monocytes, neutrophilsand lymphocytes from microscope slides, photomicrographsand electron micrographs6 state that water is the main component of blood and tissuefluid and relate the properties of water to its role in transportin mammals, limited to solvent action and high specific heatcapacity7 state the functions of tissue fluid and describe the formationof tissue fluid in a capillary network1 describe the role of red blood cells in transporting oxygen andcarbon dioxide with reference to the roles of:• haemoglobin• carbonic anhydrase• the formation of haemoglobinic acid• the formation of carbaminohaemoglobin2 describe the chloride shift and explain the importance of thechloride shift3 describe the role of plasma in the transport of carbon dioxide4 describe and explain the oxygen dissociation curve of adulthaemoglobin5 explain the importance of the oxygen dissociation curveat partial pressures of oxygen in the lungs and in respiringtissues6 describe the Bohr shift and explain the importance of theBohr shift1 describe the external and internal structure of the mammalianheart2 explain the differences in the thickness of the walls of the:• atria and ventricles• left ventricle and right ventricle3 describe the cardiac cycle, with reference to the relationshipbetween blood pressure changes during systole and diastoleand the opening and closing of valves4 explain the roles of the sinoatrial node, the atrioventricularnode and the Purkyne tissue in the cardiac cycle (knowledgeof nervous and hormonal control is not expected)1 describe the structure of the human gas exchange system,limited to:• lungs• trachea• bronchi• bronchioles• alveoli• capillary network2 describe the distribution in the gas exchange systemof cartilage, ciliated epithelium, goblet cells, squamousepithelium of alveoli, smooth muscle and capillaries3 recognise cartilage, ciliated epithelium, goblet cells,squamous epithelium of alveoli, smooth muscle andcapillaries in microscope slides, photomicrographs andelectron micrographs4 recognise trachea, bronchi, bronchioles and alveoli inmicroscope slides, photomicrographs and electronmicrographs and make plan diagrams of transverse sectionsof the walls of the trachea and bronchus5 describe the functions of ciliated epithelial cells, goblet cellsand mucous glands in maintaining the health of the gasexchange system6 describe the functions in the gas exchange system ofcartilage, smooth muscle, elastic fibres and squamousepithelium7 describe gas exchange between air in the alveoli and blood inthe capillaries

1 explain what is meant by homeostasis and the importance ofhomeostasis in mammals2 explain the principles of homeostasis in terms of internal andexternal stimuli, receptors, coordination systems (nervoussystem and endocrine system), effectors (muscles and glands)and negative feedback3 state that urea is produced in the liver from the deamination ofexcess amino acids4 describe the structure of the human kidney, limited to:• fibrous capsule• cortex• medulla• renal pelvis• ureter• branches of the renal artery and renal vein5 Identify, in diagrams, photomicrographs and electronmicrographs, the parts of a nephron and its associated bloodvessels and structures, limited to:• glomerulus• Bowman’s capsule• proximal convoluted tubule• loop of Henle• distal convoluted tubule• collecting duct6 describe and explain the formation of urine in the nephron,limited to:• the formation of glomerular filtrate by ultrafiltration in theBowman’s capsule• selective reabsorption in the proximal convoluted tubule7 relate the detailed structure of the Bowman’s capsule andproximal convoluted tubule to their functions in the formationof urine8 describe the roles of the hypothalamus, posterior pituitarygland, antidiuretic hormone (ADH), aquaporins and collectingducts in osmoregulation9 describe the principles of cell signalling using the exampleof the control of blood glucose concentration by glucagon,limited to:• binding of hormone to cell surface receptor causingconformational change• activation of G-protein leading to stimulation of adenylylcyclase• formation of the second messenger, cyclic AMP (cAMP)• activation of protein kinase A by cAMP leading to initiationof an enzyme cascade• amplification of the signal through the enzyme cascadeas a result of activation of more and more enzymes byphosphorylation• cellular response in which the final enzyme in the pathwayis activated, catalysing the breakdown of glycogen10 explain how negative feedback control mechanisms regulateblood glucose concentration, with reference to the effectsof insulin on muscle cells and liver cells and the effect ofglucagon on liver cells11 explain the principles of operation of test strips andbiosensors for measuring the concentration of glucose inblood and urine, with reference to glucose oxidase andperoxidase enzymes

1 describe the features of the endocrine system with referenceto the hormones ADH, glucagon and insulin (see 14.1.8, 14.1.9and 14.1.10)2 compare the features of the nervous system and theendocrine system3 describe the structure and function of a sensory neuroneand a motor neurone and state that intermediate neuronesconnect sensory neurones and motor neurones4 outline the role of sensory receptor cells in detecting stimuliand stimulating the transmission of impulses in sensoryneurones5 describe the sequence of events that results in an actionpotential in a sensory neurone, using a chemoreceptor cell ina human taste bud as an example6 describe and explain changes to the membrane potential ofneurones, including:• how the resting potential is maintained• the events that occur during an action potential• how the resting potential is restored during the refractoryperiod7 describe and explain the rapid transmission of an impulse in amyelinated neurone with reference to saltatory conduction8 explain the importance of the refractory period in determiningthe frequency of impulses9 describe the structure of a cholinergic synapse and explainhow it functions, including the role of calcium ions10 describe the roles of neuromuscular junctions, the T-tubulesystem and sarcoplasmic reticulum in stimulating contractionin striated muscle11 describe the ultrastructure of striated muscle with referenceto sarcomere structure using electron micrographs anddiagrams12 explain the sliding filament model of muscular contractionincluding the roles of troponin, tropomyosin, calcium ions andATP

Understandings:• The contraction of circular and longitudinal muscle of the small intestinemixes the food with enzymes and moves it along the gut.• The pancreas secretes enzymes into the lumen of the small intestine.• Enzymes digest most macromolecules in food into monomers in the smallintestine.• Villi increase the surface area of epithelium over which absorption is carriedout.• Villi absorb monomers formed by digestion as well as mineral ions andvitamins.• Different methods of membrane transport are required to absorb differentnutrients.Applications and skills:• Application: Processes occurring in the small intestine that result in thedigestion of starch and transport of the products of digestion to the liver.• Application: Use of dialysis tubing to model absorption of digested food inthe intestine.Skill: Production of an annotated diagram of the digestive system.• Skill: Identification of tissue layers in transverse sections of the small intestineviewed with a microscope or in a micrographUnderstandings:• Arteries convey blood at high pressure from the ventricles to the tissues ofthe body.• Arteries have muscle cells and elastic fibres in their walls.• The muscle and elastic fibres assist in maintaining blood pressure betweenpump cycles.• Blood flows through tissues in capillaries. Capillaries have permeable wallsthat allow exchange of materials between cells in the tissue and the blood inthe capillary.• Veins collect blood at low pressure from the tissues of the body and return itto the atria of the heart.• Valves in veins and the heart ensure circulation of blood by preventingbackflow.• There is a separate circulation for the lungs.• The heart beat is initiated by a group of specialized muscle cells in the rightatrium called the sinoatrial node.• The sinoatrial node acts as a pacemaker.• The sinoatrial node sends out an electrical signal that stimulates contractionas it is propagated through the walls of the atria and then the walls of theventricles.• The heart rate can be increased or decreased by impulses brought to theheart through two nerves from the medulla of the brain.• Epinephrine increases the heart rate to prepare for vigorous physical activityApplications and skills:• Application: William Harvey’s discovery of the circulation of the blood withthe heart acting as the pump.• Application: Pressure changes in the left atrium, left ventricle and aortaduring the cardiac cycle.• Application: Causes and consequences of occlusion of the coronary arteries.• Skill: Identification of blood vessels as arteries, capillaries or veins from thestructure of their walls.• Skill: Recognition of the chambers and valves of the heart and the bloodvessels connected to it in dissected hearts or in diagrams of heart structure.

Understandings:• Ventilation maintains concentration gradients of oxygen and carbon dioxidebetween air in alveoli and blood flowing in adjacent capillaries.• Type I pneumocytes are extremely thin alveolar cells that are adapted tocarry out gas exchange.• Type II pneumocytes secrete a solution containing surfactant that creates amoist surface inside the alveoli to prevent the sides of the alveolus adheringto each other by reducing surface tension.• Air is carried to the lungs in the trachea and bronchi and then to the alveoli inbronchioles.• Muscle contractions cause the pressure changes inside the thorax that forceair in and out of the lungs to ventilate them.• Different muscles are required for inspiration and expiration because musclesonly do work when they contract.Applications and skills:• Application: Causes and consequences of lung cancer.• Application: Causes and consequences of emphysema.• Application: External and internal intercostal muscles, and diaphragm andabdominal muscles as examples of antagonistic muscle action.• Skill: Monitoring of ventilation in humans at rest and after mild and vigorousexercise.

Understandings:• Insulin and glucagon are secreted by β and α cells of the pancreasrespectively to control blood glucose concentration.• Thyroxin is secreted by the thyroid gland to regulate the metabolic rate andhelp control body temperature.• Leptin is secreted by cells in adipose tissue and acts on the hypothalamus ofthe brain to inhibit appetite.• Melatonin is secreted by the pineal gland to control circadian rhythms.• A gene on the Y chromosome causes embryonic gonads to develop as testesand secrete testosterone.• Testosterone causes pre-natal development of male genitalia and both spermproduction and development of male secondary sexual characteristics duringpuberty.• Estrogen and progesterone cause pre-natal development of femalereproductive organs and female secondary sexual characteristics duringpuberty.• The menstrual cycle is controlled by negative and positive feedbackmechanisms involving ovarian and pituitary hormones.Applications and skills:• Application: Causes and treatment of Type I and Type II diabetes.• Application: Testing of leptin on patients with clinical obesity and reasons forthe failure to control the disease.Application: Causes of jet lag and use of melatonin to alleviate it.• Application: The use in IVF of drugs to suspend the normal secretion ofhormones, followed by the use of artificial doses of hormones to inducesuperovulation and establish a pregnancy.• Application: William Harvey’s investigation of sexual reproduction in deer.• Skill: Annotate diagrams of the male and female reproductive system to shownames of structures and their functions.

Understandings:• Bones and exoskeletons provide anchorage for muscles and act as levers.• Synovial joints allow certain movements but not others.• Movement of the body requires muscles to work in antagonistic pairs.• Skeletal muscle fibres are multinucleate and contain specialized endoplasmicreticulum.• Muscle fibres contain many myofibrils.• Each myofibril is made up of contractile sarcomeres.• The contraction of the skeletal muscle is achieved by the sliding of actin andmyosin filaments.• ATP hydrolysis and cross bridge formation are necessary for the filaments toslide.• Calcium ions and the proteins tropomyosin and troponin control musclecontractions.Applications and skills:• Application: Antagonistic pairs of muscles in an insect leg.• Skill: Annotation of a diagram of the human elbow.• Skill: Drawing labelled diagrams of the structure of a sarcomere.• Skill: Analysis of electron micrographs to find the state of contraction ofmuscle fibres.Understandings:• Animals are either osmoregulators or osmoconformers.• The Malpighian tubule system in insects and the kidney carry outosmoregulation and removal of nitrogenous wastes.• The composition of blood in the renal artery is different from that in the renalvein.• The ultrastructure of the glomerulus and Bowman’s capsule facilitateultrafiltration.• The proximal convoluted tubule selectively reabsorbs useful substances byactive transport.• The loop of Henle maintains hypertonic conditions in the medulla.• ADH controls reabsorption of water in the collecting duct.• The length of the loop of Henle is positively correlated with the need forwater conservation in animals.• The type of nitrogenous waste in animals is correlated with evolutionaryhistory and habitat.Applications and skills:• Application: Consequences of dehydration and overhydration.• Application: Treatment of kidney failure by hemodialysis or kidney transplant.• Application: Blood cells, glucose, proteins and drugs are detected in urinarytests.• Skill: Drawing and labelling a diagram of the human kidney.• Skill: Annotation of diagrams of the nephronUnderstandings:• Spermatogenesis and oogenesis both involve mitosis, cell growth, two divisions of meiosis anddifferentiation.• Processes in spermatogenesis and oogenesis result in different numbers of gametes with different amountsof cytoplasm.• Fertilization in animals can be internal or external.• Fertilization involves mechanisms that prevent polyspermy.• Implantation of the blastocyst in the endometrium is essential for the continuation of pregnancy.• HCG stimulates the ovary to secrete progesterone during early pregnancy.• The placenta facilitates the exchange of materials between the mother and fetus.• Estrogen and progesterone are secreted by the placenta once it has formed.• Birth is mediated by positive feedback involving estrogen and oxytocin.Applications and skills:• Application: The average 38-week pregnancy in humans can be positioned on a graph showing thecorrelation between animal size and the development of the young at birth for other mammals.• Skill: Annotation of diagrams of seminiferous tubule and ovary to show the stages of gametogenesis.• Skill: Annotation of diagrams of mature sperm and egg to indicate functions

Understandings:• Essential nutrients cannot be synthesized by the body, therefore they have tobe included in the diet.• Dietary minerals are essential chemical elements.• Vitamins are chemically diverse carbon compounds that cannot besynthesized by the body.• Some fatty acids and some amino acids are essential.• Lack of essential amino acids affects the production of proteins.• Malnutrition may be caused by a deficiency, imbalance or excess of nutrientsin the diet.• Appetite is controlled by a centre in the hypothalamus.• Overweight individuals are more likely to suffer hypertension and type IIdiabetes.• Starvation can lead to breakdown of body tissue.Applications and skills:• Application: Production of ascorbic acid by some mammals, but not othersthat need a dietary supply.• Application: Cause and treatment of phenylketonuria (PKU).Application: Lack of Vitamin D or calcium can affect bone mineralization andcause rickets or osteomalacia.• Application: Breakdown of heart muscle due to anorexia.• Application: Cholesterol in blood as an indicator of the risk of coronary heartdisease.• Skill: Determination of the energy content of food by combustion.• Skill: Use of databases of nutritional content of foods and software tocalculate intakes of essential nutrients from a daily diet.Understandings:• Nervous and hormonal mechanisms control the secretion of digestive juices.• Exocrine glands secrete to the surface of the body or the lumen of the gut.• The volume and content of gastric secretions are controlled by nervous andhormonal mechanisms.• Acid conditions in the stomach favour some hydrolysis reactions and help tocontrol pathogens in ingested food.• The structure of cells of the epithelium of the villi is adapted to theabsorption of food.• The rate of transit of materials through the large intestine is positivelycorrelated with their fibre content.• Materials not absorbed are egested.Applications and skills:• Application: The reduction of stomach acid secretion by proton pumpinhibitor drugs.• Application: Dehydration due to cholera toxin.• Application: Helicobacter pylori infection as a cause of stomach ulcers.• Skill: Identification of exocrine gland cells that secrete digestive juices andvillus epithelium cells that absorb digested foods from electron micrographs.Understandings:• The liver removes toxins from the blood and detoxifies them.• Components of red blood cells are recycled by the liver.• The breakdown of erythrocytes starts with phagocytosis of red blood cells byKupffer cells.• Iron is carried to the bone marrow to produce hemoglobin in new red bloodcells.• Surplus cholesterol is converted to bile salts.• Endoplasmic reticulum and Golgi apparatus in hepatocytes produce plasmaproteins.• The liver intercepts blood from the gut to regulate nutrient levels.• Some nutrients in excess can be stored in the liver.Applications and skills:• Application: Causes and consequences of jaundice.• Application: Dual blood supply to the liver and differences between sinusoidsand capillaries.Understandings:• Structure of cardiac muscle cells allows propagation of stimuli through theheart wall.• Signals from the sinoatrial node that cause contraction cannot pass directlyfrom atria to ventricles.• There is a delay between the arrival and passing on of a stimulus at theatrioventricular node.• This delay allows time for atrial systole before the atrioventricular valves close.• Conducting fibres ensure coordinated contraction of the entire ventricle wall.• Normal heart sounds are caused by the atrioventricular valves and semilunarvalves closing causing changes in blood flow.Applications and skills:• Application: Use of artificial pacemakers to regulate the heart rate.• Application: Use of defibrillation to treat life-threatening cardiac conditions.• Application: Causes and consequences of hypertension and thrombosis.• Skill: Measurement and interpretation of the heart rate under differentconditions.• Skill: Interpretation of systolic and diastolic blood pressure measurements.• Skill: Mapping of the cardiac cycle to a normal ECG trace.• Skill: Analysis of epidemiological data relating to the incidence of coronaryheart disease.Understandings:• Endocrine glands secrete hormones directly into the bloodstream.• Steroid hormones bind to receptor proteins in the cytoplasm of the targetcell to form a receptor–hormone complex.• The receptor–hormone complex promotes the transcription of specificgenes.• Peptide hormones bind to receptors in the plasma membrane of the targetcell.• Binding of hormones to membrane receptors activates a cascade mediatedby a second messenger inside the cell.• The hypothalamus controls hormone secretion by the anterior and posteriorlobes of the pituitary gland.• Hormones secreted by the pituitary control growth, developmental changes,reproduction and homeostasis.Applications and skills:• Application: Some athletes take growth hormones to build muscles.• Application: Control of milk secretion by oxytocin and prolactinUnderstandings:• Oxygen dissociation curves show the affinity of hemoglobin for oxygen.• Carbon dioxide is carried in solution and bound to hemoglobin in the blood.• Carbon dioxide is transformed in red blood cells into hydrogencarbonateions.• The Bohr shift explains the increased release of oxygen by hemoglobin inrespiring tissues.• Chemoreceptors are sensitive to changes in blood pH.• The rate of ventilation is controlled by the respiratory control centre in themedulla oblongata.• During exercise the rate of ventilation changes in response to the amount ofCO2 in the blood.• Fetal hemoglobin is different from adult hemoglobin allowing the transfer ofoxygen in the placenta onto the fetal hemoglobin.Applications and skills:• Application: Consequences of high altitude for gas exchange.• Application: pH of blood is regulated to stay within the narrow range of 7.35to 7.45.• Application: Causes and treatments of emphysema.• Skill: Analysis of dissociation curves for hemoglobin and myoglobin.• Skill: Identification of pneumocytes, capillary endothelium cells and bloodcells in light micrographs and electron micrographs of lung tissue.

• Define the respiratory surface and list its properties

• Describe the main structural features and functions of the components of human respiratory system.

• Describe the ventilation mechanism in humans.

• State lung volumes and capacities.

• Explain how breathing is controlled.

• Describe the transport of oxygen and carbon dioxide through blood.

• Describe the role of respiratory pigments.

• State the causes, symptoms and treatment of upper Respiratory Tract Infections (sinusitis, otitis media)and lower Respiratory Tract Infections (pneumonia, pulmonary tuberculosis).

• Describe the disorders of lungs (emphysema and lung cancer).

• List the effects of smoking on respiratory system

• Describe three elements i.e. receptors, control center and effectors which operate homeostatic mechanisms.

• Relate the homeostatic mechanisms with the negative and positive feedback systems.

• Differentiate between osmoconformers and osmoregulators.

• Define osmoregulation.

• Explain the problems faced by osmoregulators.

• Explain the different methods of osmoregulation found in freshwater, marine water and terrestrial

• List various nitrogenous compounds excreted during the process of excretion.

• Explain the nature of excretory products in relation to habitat.

• Explain different organs of urinary system.

• Describe the structure of kidney and relate it with its function.

• Explain the detailed structure of nephron.

• Explain the processes of glomerular filtration, selective re-absorption and tubular secretion as the events in kidney functioning.

• Explain that concentration of urine is regulated by counter-current and hormonal mechanisms.

• Justify the functioning of kidneys as both excretion and osmoregulation.

• Compare the function of two major capillary beds in kidneys i.e. glomerular capillaries and peritubular capillaries.

• List urinary tract infections and the bacteria responsible.

• Explain the causes and treatments of kidney stones.

• Outline the causes of kidney failure.

• Explain in detail the mechanism and problems related to dialysis.

• Describe the principles and the problems associated with kidney transplant.

• Define theremoregulation and explain its needs.

• Classify animals on the basis of the source of body’s heat i.e. ectotherms and endotherms.

• Classify the animals on the bases of the ability to thermoregulate i.e. poikilotherms and homeotherms.

• Describe the regulatory strategies in man for thermoregulation.

• Describe the structure of bone and compare it with that of cartilage.

• Explain the functions of osteoblasts, osteoclasts and osteocytes.

• Identify the main divisions of human skeleton.

• List the bones of appendicular and axial skeleton of man.

• Describe three types of joints i.e. fibrous joints, cartilaginous joints and synovial joints and give example of each.

• Describe the disorders of human skeleton (disc-slip, spondylosis, sciatica, arthritis) and their causes.

• State different types of fractures (simple, compound and complicated) and describe the repair process of simple fractures.

• Describe the injuries in joints (dislocation and sprain) and their first aid treatment.

• Describe the first-aid treatment for fracture.

• Compare smooth muscles, cardiac muscles and skeletal muscles.

• Explain the ultra-structure of the skeletal muscle.

• Explain the sliding filaments model of muscle contraction.

• Describe the action of antagonistic muscles in the movement of knee joint.

• Explain muscle fatigue, cramps and tetany.

• Differentiate between tetanus and muscle tetany.

• Describe the mechanical and chemical digestion in oral cavity.

• Explain swallowing and peristalsis.

• Describe the structure of stomach and relate each component with the mechanical and chemical digestion in stomach.

• Explain the role of nervous system and gastrin hormone on the secretion of gastric juice.

• Describe the major actions carried out on food in the three regions of the small intestine.

• Explain the absorption of digested products from the small intestine lumen to the blood capillaries and lacteals of the villi.

• Describe the component parts of large intestine with their respective roles.

• Correlate the involuntary reflex for egestion in infants and the voluntary control in adults.

• Explain the storage and metabolic role of liver.

• Describe composition of bile and relate the constituents with respective roles.

• Outline the structure of pancreas and explain its function as an exocrine gland.

• Relate the secretion of bile and pancreatic juice with the secretin hormone.

• State the location of heart in the body and define the role of pericardium.

• Describe the structure of the walls of heart and rationalize the thickness of the walls of each chamber.

• Describe the flow of blood through heart as regulated by the valves.

• State the phases of heartbeat.

• Explain the role of SA node, AV node and Purkinji fibers in controlling the heartbeat.

• List the principles and uses of Electrocardiogram.

• Describe the detailed structure of arteries, veins and capillaries.

• Describe the role of arterioles in vasoconstriction and vasodilation.

• Describe the role of precapillary sphincters in regulating the flow of blood through capillaries.

• Trace the path of the blood through the pulmonary and systemic circulation (coronary, hepatic-portal and renal circulation).

• Compare the rate of blood flow through arteries, arterioles, capillaries, venules and veins.

• Define blood pressure and explain its periods of systolic and diastolic pressure.

• State the role of baroreceptors and volume receptors in regulating the blood pressure.

• Define the term thrombus and differentiate between thrombus and embolus.

• Identify the factors causing atherosclerosis and arteriosclerosis.

• Categorize Angina pectoris, heart attack, and heart failure as the stages of cardiovascular disease development.

• State the congenital heart problem related to the malfunctioning of cardiac valves.

• Describe the principles of angiography.

• Outline the main principles of coronary bypass, angioplasty and open-heart surgery.

• Define hypertension and describe the factors that regulate blood pressure and can lead to hypertension and hypotension.

• List the changes in life styles that can protect man from hypertension and cardiac problems.

• Describe the formation, composition and function of intercellular fluid.

• Compare the composition of intercellular fluid with that of lymph.

• State the structure and role of lymph capillaries, lymph vessels and lymph trunks.

• Describe the role of lymph vessels (lacteals) present in villi.

• Describe the functions of lymph nodes and state the role of spleen as containing lymphoid tissue.

 

How does the human body function? How do various systems coordinate inside the human body?

Students must learn the basic knowledge of human biology.

 

Neuroscience & the Endocrine System

Understanding• Recognize receptors as transducers sensitive to various stimuli.• Trace the path of a message transmitted to the CNS for processing.• Identify the three neurons (sensory, intermediate, motor) involved in nervous transmission.• Identify muscles and glands as the effectors.Skills(Initiating and Planning)• Predict from every day experience what various kinds of receptor can be found in human body.Understanding• Describe the detailed structure of a sensory neuron, associative and a motor neuron and relate thespecialization in structures with functions.• Differentiate between myelinated and non-myelinated neurons.• Explain the function of the three types of neurons with the help of a reflex arc.Skills(Interpreting and Communication)• Draw and label the structure of three kinds of neuronUnderstanding• Define nerve impulse.• Describe the generation and transmission of nerve impulse.• Name the factors responsible for the resting membrane potential of neuron.• Evaluate from a graph the phenomena of polarization, depolarization and hyperpolarisation ofmembrane.• Compare the velocities of nerve impulse in the axon membrane and in the synaptic cleft.• Describe the role of local circuits in saltatory conduction of nerve impulse.Understanding• Describe the structure of synapse.• Explain synaptic transmission of nerve impulse.• Classify neurotransmitters as inhibitory and excitatory and list some common examples.Understanding• Identify the main components of the nervous system.• Explain briefly the functions of major divisions of brain.• Describe the architecture of human brain and compare its sectional view with that of the spinal cord.• Describe cranial and spinal nerves in man.• Explain the structure, types and functions of autonomic nervous system.• Explain the structure and functioning of the receptors for smell, taste and touch / pain.Skills(Interpreting and Communication)• Draw a labeled diagram of the human brain.• Identify different components in the diagram of CNS and PNS.Understanding• Define narcotic drugs as agents that interact with the normal nervous activity.• Compare the use and abuse of drugs with respect to heroine, Cannabis, nicotine, alcohol and inhalantslike nail polish remover and glue.• Define and explain the terms; drug addiction and drug tolerance with reference to caffeine and nicotine.• Associate the effects of drug addiction and tolerance with the functioning of nervous system.• Describe withdrawal symptoms of alcohol.Understanding• Classify nervous disorders into vascular, infectious, structural, functional and degenerative disorders• Describe the causes, symptoms and treatment one type of each category of disorders outlined above.(e.g., stroke as vascular, meningitis as infectious, brain tumor as structural, headache as functional, andAlzheimer disease as degenerative disorder).• Explain the principles of the important diagnostic tests for nervous disorders i.e. EEG, CT scan and MRI.Skills(Interpreting and Communication)• Conceptualize the activity of brain as an electrical activity, which can be recorded using magnets andtomography.• Compare the MRI scan of the brain of a sleeping human with that of a fully awake individual.Science Technology and Society Connections• Justify the way nervous system helps to coordinate complex and intricate movements of hand to play apiano, or write alphabets.• Ascertain the effect of nerve gas as an inhibitor of acetylcholinesterase.• Justify that the development of a modern computer is in fact a product of the understanding of the waynervous coordination occurs in complex organisms like humans.• Describe how this knowledge has helped humans to treat diseases like epilepsy, paralysis

1 describe the features of the endocrine system with referenceto the hormones ADH, glucagon and insulin (see 14.1.8, 14.1.9and 14.1.10)2 compare the features of the nervous system and theendocrine system3 describe the structure and function of a sensory neuroneand a motor neurone and state that intermediate neuronesconnect sensory neurones and motor neurones4 outline the role of sensory receptor cells in detecting stimuliand stimulating the transmission of impulses in sensoryneurones5 describe the sequence of events that results in an actionpotential in a sensory neurone, using a chemoreceptor cell ina human taste bud as an example6 describe and explain changes to the membrane potential ofneurones, including:• how the resting potential is maintained• the events that occur during an action potential• how the resting potential is restored during the refractoryperiod7 describe and explain the rapid transmission of an impulse in amyelinated neurone with reference to saltatory conduction8 explain the importance of the refractory period in determiningthe frequency of impulses9 describe the structure of a cholinergic synapse and explainhow it functions, including the role of calcium ions10 describe the roles of neuromuscular junctions, the T-tubulesystem and sarcoplasmic reticulum in stimulating contractionin striated muscle11 describe the ultrastructure of striated muscle with referenceto sarcomere structure using electron micrographs anddiagrams12 explain the sliding filament model of muscular contractionincluding the roles of troponin, tropomyosin, calcium ions andATP

Understandings:• Endocrine glands secrete hormones directly into the bloodstream.• Steroid hormones bind to receptor proteins in the cytoplasm of the targetcell to form a receptor–hormone complex.• The receptor–hormone complex promotes the transcription of specificgenes.• Peptide hormones bind to receptors in the plasma membrane of the targetcell.• Binding of hormones to membrane receptors activates a cascade mediatedby a second messenger inside the cell.• The hypothalamus controls hormone secretion by the anterior and posteriorlobes of the pituitary gland.• Hormones secreted by the pituitary control growth, developmental changes,reproduction and homeostasis.Applications and skills:• Application: Some athletes take growth hormones to build muscles.• Application: Control of milk secretion by oxytocin and prolactin

Understandings:• Neurons transmit electrical impulses.• The myelination of nerve fibres allows for saltatory conduction.• Neurons pump sodium and potassium ions across their membranes togenerate a resting potential.• An action potential consists of depolarization and repolarization of the neuron.• Nerve impulses are action potentials propagated along the axons of neurons.• Propagation of nerve impulses is the result of local currents that cause eachsuccessive part of the axon to reach the threshold potential.• Synapses are junctions between neurons and between neurons and receptoror effector cells.• When presynaptic neurons are depolarized they release a neurotransmitterinto the synapse.• A nerve impulse is only initiated if the threshold potential is reached.Applications and skills:• Application: Secretion and reabsorption of acetylcholine by neurons at synapses.• Application: Blocking of synaptic transmission at cholinergic synapses ininsects by binding of neonicotinoid pesticides to acetylcholine receptors.• Skill: Analysis of oscilloscope traces showing resting potentials and actionpotentials.Understandings:• Insulin and glucagon are secreted by β and α cells of the pancreasrespectively to control blood glucose concentration.• Thyroxin is secreted by the thyroid gland to regulate the metabolic rate andhelp control body temperature.• Leptin is secreted by cells in adipose tissue and acts on the hypothalamus ofthe brain to inhibit appetite.• Melatonin is secreted by the pineal gland to control circadian rhythms.• A gene on the Y chromosome causes embryonic gonads to develop as testesand secrete testosterone.• Testosterone causes pre-natal development of male genitalia and both spermproduction and development of male secondary sexual characteristics duringpuberty.• Estrogen and progesterone cause pre-natal development of femalereproductive organs and female secondary sexual characteristics duringpuberty.• The menstrual cycle is controlled by negative and positive feedbackmechanisms involving ovarian and pituitary hormones.Applications and skills:• Application: Causes and treatment of Type I and Type II diabetes.• Application: Testing of leptin on patients with clinical obesity and reasons forthe failure to control the disease.Application: Causes of jet lag and use of melatonin to alleviate it.• Application: The use in IVF of drugs to suspend the normal secretion ofhormones, followed by the use of artificial doses of hormones to inducesuperovulation and establish a pregnancy.• Application: William Harvey’s investigation of sexual reproduction in deer.• Skill: Annotate diagrams of the male and female reproductive system to shownames of structures and their functions.

OPTION:

Understandings:• Innate behaviour is inherited from parents and so develops independently ofthe environment.• Autonomic and involuntary responses are referred to as reflexes.• Reflex arcs comprise the neurons that mediate reflexes.• Reflex conditioning involves forming new associations.• Learned behaviour develops as a result of experience.• Imprinting is learning occurring at a particular life stage and is independentof the consequences of behaviour.• Operant conditioning is a form of learning that consists of trial and errorexperiences.• Learning is the acquisition of skill or knowledge.• Memory is the process of encoding, storing and accessing information.Applications and skills:• Application: Withdrawal reflex of the hand from a painful stimulus.• Application: Pavlov’s experiments into reflex conditioning in dogs.Application: The role of inheritance and learning in the development ofbirdsong.• Skill: Analysis of data from invertebrate behaviour experiments in terms ofthe effect on chances of survival and reproduction.• Skill: Drawing and labelling a diagram of a reflex arc for a pain withdrawalreflex.Understandings:• Some neurotransmitters excite nerve impulses in postsynaptic neurons andothers inhibit them.• Nerve impulses are initiated or inhibited in post-synaptic neurons as a resultof summation of all excitatory and inhibitory neurotransmitters received frompresynaptic neurones.• Many different slow-acting neurotransmitters modulate fast synaptictransmission in the brain.• Memory and learning involve changes in neurones caused by slow-actingneurotransmitters.• Psychoactive drugs affect the brain by either increasing or decreasingpostsynaptic transmission.• Anesthetics act by interfering with neural transmission between areas ofsensory perception and the CNS.• Stimulant drugs mimic the stimulation provided by the sympathetic nervoussystem.• Addiction can be affected by genetic predisposition, social environment anddopamine secretion.Applications and skills:• Application: Effects on the nervous system of two stimulants and twosedatives.• Application: The effect of anesthetics on awareness.Application: Endorphins can act as painkillers.• Skill: Evaluation of data showing the impact of MDMA (ecstasy) on serotoninand dopamine metabolism in the brain.Understandings:• Ethology is the study of animal behaviour in natural conditions.• Natural selection can change the frequency of observed animal behaviour.• Behaviour that increases the chances of survival and reproduction willbecome more prevalent in a population.• Learned behaviour can spread through a population or be lost from it morerapidly than innate behaviour.Applications and skills:• Application: Migratory behaviour in blackcaps as an example of the geneticbasis of behaviour and its change by natural selection.• Application: Blood sharing in vampire bats as an example of the developmentof altruistic behaviour by natural selection.• Application: Foraging behaviour in shore crabs as an example of increasingchances of survival by optimal prey choice.• Application: Breeding strategies in coho salmon populations as an exampleof behaviour affecting chances of survival and reproduction.• Application: Courtship in birds of paradise as an example of mate selection.• Application: Synchronized oestrus in female lions in a pride as an example ofinnate behaviour that increases the chances of survival and reproduction ofoffspring.• Application: Feeding on cream from milk bottles in blue tits as an example ofthe development and loss of learned behaviour.

• Recognize receptors as transducers sensitive to various stimuli.

• Trace the path of a message transmitted to the CNS for processing.

• Identify the three neurons (sensory, intermediate, motor) involved in nervous transmission.

• Identify muscles and glands as the effectors.

• Describe the detailed structure of a sensory neuron, associative and a motor neuron and relate the specialization in structures with functions.

• Differentiate between myelinated and non-myelinated neurons.

• Explain the function of the three types of neurons with the help of a reflex arc.

• Define nerve impulse.

• Describe the generation and transmission of nerve impulse.

• Name the factors responsible for the resting membrane potential of neuron.

• Evaluate from a graph the phenomena of polarization, depolarization and hyperpolarisation of membrane.

• Compare the velocities of nerve impulse in the axon membrane and in the synaptic cleft.

• Describe the role of local circuits in saltatory conduction of nerve impulse.

• Describe the structure of synapse.

• Explain synaptic transmission of nerve impulse.

• Classify neurotransmitters as inhibitory and excitatory and list some common examples.

• Identify the main components of the nervous system.

• Explain briefly the functions of major divisions of brain.

• Describe the architecture of human brain and compare its sectional view with that of the spinal cord.

• Describe cranial and spinal nerves in man.

• Explain the structure, types and functions of autonomic nervous system.

• Explain the structure and functioning of the receptors for smell, taste and touch / pain.

• Define narcotic drugs as agents that interact with the normal nervous activity.

• Compare the use and abuse of drugs with respect to heroine, Cannabis, nicotine, alcohol and inhalants like nail polish remover and glue.

• Define and explain the terms; drug addiction and drug tolerance with reference to caffeine and nicotine.

• Associate the effects of drug addiction and tolerance with the functioning of nervous system.

• Describe why fentanyl is so harmful for the human body.

• Describe how pain medicines can reduce or numb pain in the human body.

• Describe why certain pain medications are addictive.

• Describe withdrawal symptoms of alcohol.

• Classify nervous disorders into vascular, infectious, structural, functional and degenerative disorders

• Describe the causes, symptoms and treatment one type of each category of disorders outlined above (e.g., stroke as vascular, meningitis as infectious, brain tumor as structural, headache as functional, and Alzheimer disease as degenerative disorder).

• Explain the principles of the important diagnostic tests for nervous disorders i.e. EEG, CT scan and MRI.

• State the role of hormones as chemical messengers.

• Describe the chemical nature of hormones and correlate it with important hormones.

• Trace the path of the chemical message from its release from the endocrine gland to its action at the target site.

• Explain the two modes of hormone action at the cells of target site.

• Locate the following endocrine glands in human body; pituitary, thyroid, parathyroid, pancreas, adrenal, gonads.

• Name the hormonal secretions of the above-mentioned glands.

• Outline the major functions of the hormones of above mentioned glands and also relate the problems associated with the imbalance of these hormones.

• Explain the neurosecretory role of hypothalamus.

• Describe the functions of the hormones secreted by the endocrine tissue other than the mentioned above.

• Outline the concept of Feedback mechanism of hormones.

• Describe positive feedback with reference to Oxytocin and negative feedback with reference to Insulin and Glucagon.

 

Which structural features of a neuron are key to its function?

How does the human nervous sytem take in infomrationn, come to a decision and then affect a response?

Neuroscience is a key frontier for modern day biology. An increasing amount of effort and resources is going into research to decipher the mysteries of the brain and the rest of the nervous system to better understand our thought processes, how memories are made and maintained and to learn how to combat the effects of dementia, Alzheimers and other neurological disorders and diseases. Students would greatly benefit from learning modern day biology.

 

Immunity

Understanding• Describe the structural features of human skin that make it impenetrable barrier against invasion bymicrobes.• Explain how oil and sweat glands within the epidermis inhibit the growth and also kill microorganisms.• Recognize the role of the acids and enzymes of the digestive tract in killing the bacteria present in food.• State the role of the ciliated epithelium of nasal cavity and of the mucous of the bronchi and bronchiolesin trapping air borne microorganisms.Understanding• Describe the role of macrophages and neutrophils in killing bacteria.• Explain how the Natural Killer (NK) cells kill the cells that are infected by microbes and also kill cancercells.• State how the proteins of the complement system kill bacteria and how the interferons inhibit the abilityof viruses to infect cells.• State the events of the inflammatory response as one of the most generalized nonspecific defenses.• Outline the release of pyrogens by microbes and their effect on hypothalamus to boost the body’stemperature.• List the ways the fever kills microbes.Skills(Initiating and Planning)• Rationalize the inflammatory response in arthritis as an example of a misdirected immune response.• Justify why the physicians prescribe antipyretic drugs, when fever is a nonspecific defense againstmicrobial infections.Understanding• Categorize the immune system that provides specific defense and acts as the most powerful means ofresisting infection.• Identify monocytes, T-cells and B-cells as the components of the immune system.• State the inborn and acquired immunity as the two basic types of immunity.• Differentiate the two types of acquired immunity (active and passive immunity).• Identify the process of vaccination as a means to develop active acquired immunity.• Describe the roles T-cells in cell-mediated immunity.• Describe the role of B-cells in antibody-mediated immunity.• Draw the structural model of an antibody molecule.• Explain the role of memory cells in long-term immunity.• Define allergies and correlate the symptoms of allergies with the release of histamines.• Describe the autoimmune diseases.• Describe the role of T-cells and B-cells in transplant rejections.Skills(Initiating and Planning)• Justify why physicians prescribe antihistamine therapy to the patients of runny nose or skin rashes.• Explain why a transplant recipient is given immune suppressant drugs and determine what implicationsdoes this have on his life.(Analyzing and Interpreting)• Recognize phagocytes and lymphocytes under the light microscope.Science Technology and Society Connections• Describe malignant melanoma as due to the inability of tumor-infiltrating lymphocyte (TIL) to control thetumors of skin cancer and correlate it with the scientific advancements of inserting a gene of tumornecrosis factor in the lymphocyte.• Describe the discovery of monoclonal antibodies and justify how this accomplishment revolutionizedmany aspects of biological research.

1 describe the mode of action of phagocytes (macrophagesand neutrophils)2 explain what is meant by an antigen (see 4.1.3) and state thedifference between self antigens and non-self antigens3 describe the sequence of events that occurs during a primaryimmune response with reference to the roles of:• macrophages• B-lymphocytes, including plasma cells• T-lymphocytes, limited to T-helper cells and T-killer cells4 explain the role of memory cells in the secondary immuneresponse and in long-term immunity1 relate the molecular structure of antibodies to their functions2 outline the hybridoma method for the production ofmonoclonal antibodies3 outline the principles of using monoclonal antibodies in thediagnosis of disease and in the treatment of disease4 describe the differences between active immunity andpassive immunity and between natural immunity and artificialimmunity5 explain that vaccines contain antigens that stimulate immuneresponses to provide long-term immunity6 explain how vaccination programmes can help to control thespread of infectious diseases

Understandings:• Every organism has unique molecules on the surface of its cells.• Pathogens can be species-specific although others can cross species barriers.• B lymphocytes are activated by T lymphocytes in mammals.• Activated B cells multiply to form clones of plasma cells and memory cells.• Plasma cells secrete antibodies.• Antibodies aid the destruction of pathogens.• White cells release histamine in response to allergens.• Histamines cause allergic symptoms.• Immunity depends upon the persistence of memory cells.• Vaccines contain antigens that trigger immunity but do not cause the disease.• Fusion of a tumour cell with an antibody-producing plasma cell creates ahybridoma cell.• Monoclonal antibodies are produced by hybridoma cells.Applications and skills:• Application: Smallpox was the first infectious disease of humans to have beeneradicated by vaccination.• Application: Monoclonal antibodies to HCG are used in pregnancy test kits.• Application: Antigens on the surface of red blood cells stimulate antibodyproduction in a person with a different blood group.• Skill: Analysis of epidemiological data related to vaccination programmes.

• Describe the structural features of human skin that make it impenetrable barrier against invasion by microbes.

• Explain how oil and sweat glands within the epidermis inhibit the growth and also kill microorganisms.

• Recognize the role of the acids and enzymes of the digestive tract in killing the bacteria present in food.

• State the role of the ciliated epithelium of nasal cavity and of the mucous of the bronchi and bronchiolesin trapping air borne microorganisms.

• Describe the role of macrophages and neutrophils in killing bacteria.

• Explain how the Natural Killer (NK) cells kill the cells that are infected by microbes and also kill cancer cells.

• State how the proteins of the complement system kill bacteria and how the interferons inhibit the ability of viruses to infect cells.

• State the events of the inflammatory response as one of the most generalized nonspecific defenses.

• Outline the release of pyrogens by microbes and their effect on hypothalamus to boost the body’s temperature.

• List the ways the fever kills microbes.

• Categorize the immune system that provides specific defense and acts as the most powerful means of resisting infection.

• Identify monocytes, T-cells and B-cells as the components of the immune system.

• State the inborn and acquired immunity as the two basic types of immunity.

• Differentiate the two types of acquired immunity (active and passive immunity).

• Identify the process of vaccination as a means to develop active acquired immunity.

• Describe the roles T-cells in cell-mediated immunity.

• Describe the role of B-cells in antibody-mediated immunity.

• Draw the structural model of an antibody molecule.

• Explain the role of memory cells in long-term immunity.

• Define allergies and correlate the symptoms of allergies with the release of histamines.

• Describe the autoimmune diseases.

• Describe the role of T-cells and B-cells in transplant rejections.Describe the discovery of monoclonal antibodies and justify how this accomplishment revolutionized many aspects of biological research.

 

Which unique features of the immune system are key to its function?

How does the human immune system gather knowledge about any pathogens and then affect a response?

Gaining a better understanding of how the immune system works allows us to further enhance our own immunity and health. This is why it is essential that students of biology understand how our immune system functions.

 

Diseases

• Describe the causes, symptoms and treatment of gonorrhea and syphilis.

• Explain AIDS as a worldwide sexually transmitted disease.

Conceptual Linkages:

STS Connections

• Realize the affect of endocrine disrupting contaminants on the reproductive abilities.

• Become aware of the ethical implications of abortion.

• List the measures that can help to prevent transmission of HIV.

1 state that infectious diseases are caused by pathogens andare transmissible2 state the name and type of pathogen that causes each of thefollowing diseases:• cholera – caused by the bacterium Vibrio cholerae• malaria – caused by the protoctists Plasmodiumfalciparum, Plasmodium malariae, Plasmodium ovale andPlasmodium vivax• tuberculosis (TB) – caused by the bacteria Mycobacteriumtuberculosis and Mycobacterium bovis• HIV/AIDS – caused by the human immunodeficiency virus(HIV)3 explain how cholera, malaria, TB and HIV are transmitted4 discuss the biological, social and economic factors that needto be considered in the prevention and control of cholera,malaria, TB and HIV (details of the life cycle of the malarialparasite are not expected)

Understandings:• The skin and mucous membranes form a primary defence against pathogensthat cause infectious disease.• Cuts in the skin are sealed by blood clotting.• Clotting factors are released from platelets.• The cascade results in the rapid conversion of fibrinogen to fibrin bythrombin.• Ingestion of pathogens by phagocytic white blood cells gives non-specificimmunity to diseases.• Production of antibodies by lymphocytes in response to particular pathogensgives specific immunity.• Antibiotics block processes that occur in prokaryotic cells but not ineukaryotic cells.• Viruses lack a metabolism and cannot therefore be treated with antibiotics.Some strains of bacteria have evolved with genes that confer resistance toantibiotics and some strains of bacteria have multiple resistance.Applications and skills:• Application: Causes and consequences of blood clot formation in coronaryarteries.• Application: Florey and Chain’s experiments to test penicillin on bacterialinfections in mice.• Application: Effects of HIV on the immune system and methods oftransmission.

Cancer:

• Define cancer

• List how having cancer kills a human being.

• Describe how a cancer spreads through the body using blood vessels.

• Describe how a cancer spreads through the body using the lymphatic system.

• Explain how mutations can make a cancer more aggressive

• Describe why it is important to map the genome of a tumor before beginning cancer treatment

• Explain why it is better to classify a tumor based off of its accumulated genetic mutations instead of its physical location.

• Describe immuno-oncology with examples of some recent approved immune-oncology drugs. Describe how smoking increases the risk of cancer.

• Describe how screening is important for breast and prostate cancer.

Alzheimers.

• Define Alzheimers.

• Describe the current understanding of how Alzheimers begins.

• Describe how Alzheimers progresses. Explain any current treatments for Alzheimers and their mechanisms of action.

• Describe how exercise could play a role in reducing the risk of Alzheimers.

• Describe how good sleep could play a role in reducing the risk of Alzheimers.

• Describe how a good diet could play a role in reducing the risk of Alzheimers.

Covid-19.

• Describe how the Covid-19 virus is suspected of entering humans from animals

• Describe Covid-19 virus’s mechanism of action which causes respiratory problems.

• Describe how certain mutations enhanced the virulence of the Covid-19 virus.

• Describe long covid and its lasting effects on patients. Describe how mRNA vaccines protect against Covid-19.

• Describe how Russia’s Sputnik-V vaccine protects against Covid-19.

• Compare and contrast diabetes type I and II.

• Describe the harmful effects on the body of diabetes on the human body.

• Describe the role of genetics in diabetes. Describe how exercise can help in reducing the risk of diabetes.

• Describe how exercise can help reduce the severity of diabetes.

• Describe how a good diet can help in reducing the risk of diabetes.

• Describe how good diet can help reduce the severity of diabetes.

• Explain the mechanism of action of drug treatments that doctors prescribe for diabetes I.

• Explain the mechanism of action of drug treatments that doctors prescribe for diabetes II.

Lupus:

• Describe lupus.

• Explain its mechanism of action.

• Explain the mechanism of action of drug treatments that doctors prescribe for lupus.

 

Which unique features of a disease are key to its impact?

How does the knowledge of such features help in mitiagting/treating its harm.

Gaining a better understanding of diseases allows humanity to begin treating and curing them. Students need to learn disease biology in order to get a better appreciation of such major areas of interest in Biology.

 

Pharmacological Drugs

• Describe how biotechnologists are able to combat health problems by producing vaccines.

• State the role played by biotechnology in disease diagnosis (DNA/RNA probes, monoclonal antibodies).

• Describe what products biotechnologists obtain for use in disease treatment.

• Explain the current methods employed for gene therapy (ex-vivo and in-vivo methods).

• Explain with example gene therapies in the detection and treatment of some genetic diseases.

• Explain the role of successful gene therapy for cystic fibrosis.• Describe the causes, symptoms and treatment of gonorrhea and syphilis.

• Explain AIDS as a worldwide sexually transmitted disease.

Conceptual Linkages:

STS Connections

• Realize the affect of endocrine disrupting contaminants on the reproductive abilities.

• Become aware of the ethical implications of abortion.

• List the measures that can help to prevent transmission of HIV.

• Classify nervous disorders into vascular, infectious, structural, functional and degenerative disorders

• Describe the causes, symptoms and treatment one type of each category of disorders outlined above.

(e.g., stroke as vascular, meningitis as infectious, brain tumor as structural, headache as functional, and

Alzheimer disease as degenerative disorder).

• Explain the principles of the important diagnostic tests for nervous disorders i.e. EEG, CT scan and MRI.

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• Explain the drug discovery and development process.

• Explain the different classes of drugs work against HIV.

• Explain the mechanism of action of Sovaldi whcih cures Hepatitis C.

• Describe why in Harvoni, Sovaldi is combined with Gilead's ledipasvir (an NS5A inhibitor).

• Compare and contrast Harvoni with Sovaldi

• Describe advantages of monoclonal antibodies enjoy compared to other drug classes.

• Explain the mechanism of action of rituximab (Mabthera).

• Explain the term precision medicine.

• Explain the different classes of drugs work against HIV.

• Explain the mechanism of action of Sovaldi which cures Hepatitis C.

• Describe why in Harvoni, Sovaldi is combined with Gilead's ledipasvir (an NS5A inhibitor).

• Explain the mechanism of action of chimeric antigen receptor T-cell (CAR-T) therapy for leukemia.

• Describe fecal transplant and name the condition it is used to treat.

• Explain the drug discovery and development process.

• Explain the clinical trials approval process for any new drug candidate.

 

How do different classes of drugs affect their responses?

Understadning how various pharmaceutical drugs can treat and at times cure a disease is very ppwerful information as it shows biological knowledge being employed for a very useful goal - to save human lives. Gainaing this knowledge is usefula s it shows where modern day biology stands and its benefits.

 

Biostatistics and Data Presentation

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Students should be familiar with understanding basic charts and graphs.

• Sketch error bars based off of range or standard deviation for a given set of data on a bar chart.

• Deduce and sketch the appropriate type of figure or chart for a given set of data and/or experiment (bar chart, pie chart, x-y axis data figure etc).

• Make the appropriate chart in Microsoft excel with proper title, labelled axes, legend, axes units.

• Design an appropriate experiment with a control group and dependent, independent and control variables.

• Choose, implement and correctly represent the results of the correct statistical test given the nature of the data and experiment from among the following:

t-test

ANOVA

Turkey Test

Correlation

R-squared value

Welch test

 

What statistical test is best suited to statistically empowering a particular set of scienitifc data? What method of presentation is best suited to presenting a particular set of scienitifc data?

Understaning how to statistiically empower and present one's biological/scientific knowledge is absolutelt necessary for any student to be scientifically literate.

 

Climate Change

Understanding• Relate the need of the nuclear power to the scarcity of fossil fuels.• State the problems of using nuclear power (surety of safe operation and safe disposal of the wastes).• Describe the causes of the increasing concentration of carbon dioxide in the world’s atmosphere.• Correlate the increasing CO2 concentration with the global warming and describe its log term effects.• Explain the causes and effects of acid rain.• Describe the composition of the ozone layer and its role in protecting the life on earth.• State the sources of chlorofluorocarbons and their role in the depletion of ozone.• Explain the effects of ultraviolet radiation as a serious human health concern.• Narrate the incidence when one of the four reactors of the Chernobyl nuclear power plant blew up in 1986?Understanding• Distinguish between renewable and non-renewable environmental resources.• Describe how man is responsible for the depletion of environmental resources.• Describe the conventional and non-conventional energy resources.• Analyze the efforts of various government departments and NGOs to educate people for the protectionof environmental resources.Science Technology and Society Connections• Outline the advances in medical care and technology that have contributed to an increase in lifeexpectancy, and relate these developments to demographic issues.• Justify why science education has become necessary for everyone to understand the basis of man’scontinued existence and the steps man has to take to save and improve life.• Investigate the careers related to the study of environmental resources.

 

 

• Describe how climate change impacts agriculture and thus food security.

• Describe how climate change can impact ocean biology in terms of its temperature and acidity as well as the resulting harmful effects.

• Explain why carbon sink conservation and enhancement mitigate climate change.

• Describe how increasing the albedo of surface crop plants could help in mitigating global surface increases.

• Name species that have gone extinct due to climate change.

 

Why does climate change matter in a biological context.

Can biological knowledge be used to mitigate climate change's harmful effects.

With climate shcnage gaining increasing importance and impact wiht each passing day, students need to understand how it impacts biology and how best one can use biological knowledge to mitigate climate changes' impact.

 

Advanced Biotechnology

Understanding• Define gene cloning and state the steps in gene cloning.• Describe the techniques of gene cloning through recombinant DNA technology.• Explain the role of restriction endonucleases and DNA ligases in gene cloning.• Describe the selection and isolation of the gene of interest.• Explain the properties and the role of vectors in recombinant DNA technology.• State the steps for the integration of DNA insert into the vector.• Briefly state the technique applied for the selection of the vectors that take up the DNA insert.• Describe the steps involved in gene amplification through polymerase chain reaction.• Describe the procedure for the construction of genomic library.Understanding• Explain the Maxam / Gilbert procedure and the Sanger-Coulson method of DNA sequencing.• Describe the principles of Gel Electrophoresis as being used in gene sequencing.• Introduce the automated DNA sequencing as based on the Sanger-Coulson method.Understanding• Describe the purposes and mechanism of DNA analysis.Skills(Analyzing and Interpreting)• Analyze and interpret the DNA of a child by comparing it with that of two individuals in a case ofdisputed parenthood.Understanding• Describe the terms of genome analysis, genome map and genetic markers.• State the history of the human genome project admiring James Watson as its first director.• Describe the goals of the human genome project.• Predict some of the possible benefits that can be derived after the completion of the human genomeproject.Understanding• Define following terms related to plant tissue culture; explants, callus, micro-propagation, plantlets,somatic embryogenesis, somaclonal variation.• Explain tissue culture and differentiate between the organ culture and cell culture.• Differentiate between the callus culture and suspension culture techniques.• Describe the anther culture, ovary culture, meristem culture and embryo culture techniques.• Briefly describe the techniques used for, applications and limitations of animal tissue culture.Understanding• State the objectives of the production of transgenic bacteria, transgenic plants and transgenic animals.• Describe different methods applied for the introduction of DNA into plant and animals cells / embryos.• Describe the role of biotechnology in the production of insect, virus and herbicide resistant plants.• State the notable human gene transfers in different animal species and describe their potentialapplications and future prospects.• State the role of transgenic bacteria in making biotechnology products.• List some of the ecological concerns surrounding transgenic bacteria.• Describe the ways in which genetic engineering improves farm animals.Understanding• Describe how biotechnologists are able to combat health problems by producing vaccines.• State the role played by biotechnology in disease diagnosis (DNA/RNA probes, monoclonal antibodies).• Describe what products biotechnologists obtain for use in disease treatment.• Explain the current methods employed for gene therapy (ex-vivo and in-vivo methods).• Explain with example gene therapies in the detection and treatment of some genetic diseases.• Explain the role of successful gene therapy for cystic fibrosis.Understanding• Explain the scope and importance of biotechnology in promoting human welfare.• List the hazards and social / ethical implications of using gene technology in humanSTS Connections• Describe the application of polymerase chain reaction.• State the importance and limitations of DNA analysis in forensic medicine and paleontology.• Justify why the human genome project is regarded as the most ambitious project ever undertaken byman.• Describe the major findings that have arisen from the human genome project.• Predict the applications of genetic engineering in crop improvement.• Describe the role of genetic screening.• Justify the need for genetic counseling.• Describe briefly the accomplishments of the renowned genetic engineers working in private and publicinstitutions in his / her province.• Suggest measures s/he would take to solve related problems by using knowledge gained in this chapter.• Describe and analyze examples of technology that have extended or modified the scientificunderstanding of the genetic engineering.• Investigate careers that require an understanding of biotechnology and genetic engineering

1 define the term recombinant DNA2 explain that genetic engineering is the deliberate manipulationof genetic material to modify specific characteristics of anorganism and that this may involve transferring a gene into anorganism so that the gene is expressed3 explain that genes to be transferred into an organism may be:• extracted from the DNA of a donor organism• synthesised from the mRNA of a donor organism• synthesised chemically from nucleotides4 explain the roles of restriction endonucleases, DNA ligase,plasmids, DNA polymerase and reverse transcriptase in thetransfer of a gene into an organism5 explain why a promoter may have to be transferred into anorganism as well as the desired gene6 explain how gene expression may be confirmed by the use ofmarker genes coding for fluorescent products7 explain that gene editing is a form of genetic engineeringinvolving the insertion, deletion or replacement of DNA atspecific sites in the genome8 describe and explain the steps involved in the polymerasechain reaction (PCR) to clone and amplify DNA, including therole of Taq polymerase9 describe and explain how gel electrophoresis is used toseparate DNA fragments of different lengths10 outline how microarrays are used in the analysis of genomesand in detecting mRNA in studies of gene expression11 outline the benefits of using databases that provideinformation about nucleotide sequences of genes andgenomes, and amino acid sequences of proteins and proteinstructures1 explain the advantages of using recombinant human proteinsto treat disease, using the examples insulin, factor VIII andadenosine deaminase2 outline the advantages of genetic screening, using theexamples of breast cancer (BRCA1 and BRCA2), Huntington’sdisease and cystic fibrosis3 outline how genetic diseases can be treated withgene therapy, using the examples severe combinedimmunodeficiency (SCID) and inherited eye diseases4 discuss the social and ethical considerations of using geneticscreening and gene therapy in medicine1 explain that genetic engineering may help to solve the globaldemand for food by improving the quality and productivity offarmed animals and crop plants, using the examples ofGM salmon, herbicide resistance in soybean and insectresistance in cotton2 discuss the ethical and social implications of using geneticallymodified organisms (GMOs) in food production

Understandings:• Microorganisms are metabolically diverse.• Microorganisms are used in industry because they are small and have a fastgrowth rate.• Pathway engineering optimizes genetic and regulatory processes withinmicroorganisms.• Pathway engineering is used industrially to produce metabolites of interest.• Fermenters allow large-scale production of metabolites by microorganisms.• Fermentation is carried out by batch or continuous culture.• Microorganisms in fermenters become limited by their own waste products.• Probes are used to monitor conditions within fermenters.• Conditions are maintained at optimal levels for the growth of themicroorganisms being cultured.Applications and skills:• Application: Deep-tank batch fermentation in the mass production ofpenicillin.• Application: Production of citric acid in a continuous fermenter by Aspergillusniger and its use as a preservative and flavouringApplication: Biogas is produced by bacteria and archaeans from organicmatter in fermenters.• Skill: Gram staining of Gram-positive and Gram-negative bacteria.• Skill: Experiments showing zone of inhibition of bacterial growth bybactericides in sterile bacterial cultures.• Skill: Production of biogas in a small-scale fermenter.Understandings:• Transgenic organisms produce proteins that were not previously part of theirspecies’ proteome.• Genetic modification can be used to overcome environmental resistance toincrease crop yields.• Genetically modified crop plants can be used to produce novel products.• Bioinformatics plays a role in identifying target genes.• The target gene is linked to other sequences that control its expression.• An open reading frame is a significant length of DNA from a start codon to astop codon.• Marker genes are used to indicate successful uptake.• Recombinant DNA must be inserted into the plant cell and taken up by itschromosome or chloroplast DNA.• Recombinant DNA can be introduced into whole plants, leaf discs orprotoplasts.• Recombinant DNA can be introduced by direct physical and chemicalmethods or indirectly by vectors.Applications and skills:• Application: Use of tumour-inducing (Ti) plasmid of Agrobacteriumtumefaciens to introduce glyphosate resistance into soybean crops.• Application: Genetic modification of tobacco mosaic virus to allow bulkproduction of Hepatitis B vaccine in tobacco plants.Application: Production of Amflora potato (Solanum tuberosum) for paperand adhesive industries.• Skill: Evaluation of data on the environmental impact of glyphosate-tolerantsoybeans.• Skill: Identification of an open reading frame (ORF)Understandings:• Responses to pollution incidents can involve bioremediation combined withphysical and chemical procedures.• Microorganisms are used in bioremediation.• Some pollutants are metabolized by microorganisms.• Cooperative aggregates of microorganisms can form biofilms.• Biofilms possess emergent properties.• Microorganisms growing in a biofilm are highly resistant to antimicrobial agents.• Microorganisms in biofilms cooperate through quorum sensing.• Bacteriophages are used in the disinfection of water systems.Applications and skills:• Application: Degradation of benzene by halophilic bacteria such as Marinobacter.• Application: Degradation of oil by Pseudomonas.• Application: Conversion by Pseudomonas of methyl mercury into elementalmercury.• Application: Use of biofilms in trickle filter beds for sewage treatment.• Skill: Evaluation of data or media reports on environmental problems causedby biofilms.Understandings:• Infection by a pathogen can be detected by the presence of its geneticmaterial or by its antigens.• Predisposition to a genetic disease can be detected through the presence ofmarkers.• DNA microarrays can be used to test for genetic predisposition or to diagnosethe disease.• Metabolites that indicate disease can be detected in blood and urine.• Tracking experiments are used to gain information about the localization andinteraction of a desired protein.• Biopharming uses genetically modified animals and plants to produceproteins for therapeutic use.• Viral vectors can be used in gene therapy.Applications and skills:• Application: Use of PCR to detect different strains of influenza virus.• Application: Tracking tumour cells using transferin linked to luminescentprobesApplication: Biopharming of antithrombin.• Application: Use of viral vectors in the treatment of Severe CombinedImmunodeficiency (SCID).• Skill: Analysis of a simple microarray.• Skill: Interpretation of the results of an ELISA diagnostic test

• Describe how vertical food farms (soil free) work.

• Compare and contrast the advantages of vertical food farms with general agricultural practices prevalent in Pakistan.

• Explain the current state of efforts regarding growing organs in labs to be transplanted into human bodies.

• Explain the current research into anti-aging medications and treatments.

• Explain the potential of CRISPR in treating genetic diseases.

 

How can we use biological knowledge to benefit mankind?

To develop a scientifically literate student, this chapter is necessary as it leaves the student with a good understanding of not only how far biology has progressed and how much potential it has but also how it can be used to improve the lives of the student, those around him/her and their society.

 

Selected Topics

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• Explain how biological warfare occurs with examples.

• Describe how modern day biological weapons could work.

• Describe how biodefenses could work to protect from biological warfare with examples.

• Examine the hype behind the comics “genomics, transcriptomics, proteomics metabolomics”, to what extent is it valid or overblown?

• Explain synthetic biology with examples

 

How is biology used at times for nefarious purposed? How can we use biological knowledge to benefit mankind?

To develop a scientifically literate student, this chapter is important as it leaves the student with a good understanding of some of the less explored yet extremely important if unpleasant aspects of modern Biology.

 

 

 

Biology Experiment SLOs 11-12

 

2006 National Curriculum

CAIE O&A Levels 2023 - 2025

NCC 2023 SLOs

Rationale

NCC Recommended Experiment Learning Experiences

Questions for Feedback from Stakeholders

Overall Learning Objectives

 

 

Grade 11:

Manipulation, measurement and observation

Decisions relating to measurements and observations

Within an investigation, students should be able to:

• identify the independent variable and dependent variable

• decide a suitable range of values to use for the independent variable at which measurements of the

dependent variable are recorded

• decide the number of different values of the independent variable (a minimum of five) and the intervals

between them

• decide how to change the value of the independent variable

• decide how the dependent variable should be measured

• decide the number of replicates at each value

• decide on appropriate controls for the experiment or investigation

• decide which variables need to be standardised and how to standardise them. (Variables expected to have

a minimal effect, such as variation between test-tubes of the same type, do not need to be standardised.)

When using the light microscope and photomicrographs, students should be able to:

• set up a light microscope to view and observe specimens

• follow instructions to find and draw particular tissues in plant and animal specimens and label the drawings

appropriately

• follow instructions to find and draw particular cells and structures within the cells

• make a temporary slide of stained cells or tissues

• calculate actual sizes of tissues or cells from measurements of photomicrographs, using magnifications,

scale bars or representations of eyepiece graticules and stage micrometers

• estimate the number of cells or cell organelles in a given area using a sampling method, such as grids or

fields of view.

Collection of data and observations

Within an investigation, students should be able to:

• follow instructions to collect results

• consider the hazards of the procedure, including the use of any solutions and reagents, and assess the risk

as low, medium or high

• take readings to obtain accurate data (quantitative results) or observations (qualitative results).

When using the light microscope and photomicrographs, candidates should be able to:

• draw plan diagrams to show the distribution of tissues in a specimen, with no cells drawn and the correct

proportions of layers of tissues

• draw the observable features of cells in a specimen showing:

– the correct shapes

– the thicknesses of cell walls where applicable (drawn with two lines or drawn with three lines where two

cells touch)

– the relative sizes and proportions

– observable cell contents only

• measure tissue layers or cells from photomicrographs using a ruler or given scale, including representations

of eyepiece graticules

• make accurate observations from specimens including counting numbers of cells or cell organelles

• record similarities and differences between two specimens using only their observable features.

Presentation of data and observations

Recording data and observations

Within an investigation, students should be able to:

• record raw results (unprocessed) and calculated results (processed) in an appropriate table with:

– descriptive headings, including any required units (no units in body of table)

– heading for the independent variable to the left of (or above, if the table is in rows) the dependent

variable

• record quantitative data to the number of decimal places that is appropriate for the measuring instrument

used

• record qualitative observations using clear descriptions

• record calculated values (processed results) in an appropriate table.

When using the light microscope and photomicrographs, candidates should be able to:

• record the fine details of the specimen, including drawing the detailed shapes of layers or outlines of

specimens in plan diagrams and drawing the shape and position of observable cell organelles in cells.

Display of calculation and reasoning

Within an investigation and when using the light microscope and photomicrographs, students should be able

to:

• display calculations clearly, showing all the steps and reasoning

• use the correct number of significant figures for calculated quantities. This should be the same as, or one

more than, the smallest number of significant figures in the data used in the calculation.

Layout of data and observations

Within an investigation, candidates should be able to:

• display data as a graph (continuous data), bar chart (discontinuous or categoric) or histogram (frequency

data)

• draw a graph, bar chart or histogram clearly and accurately with:

– the independent variable on the x-axis and the dependent variable on the y-axis

– axes labelled to match the relevant table headings, including units where appropriate

– a scale where both axes should use most or all of the grid available and allow the graph to be read

easily to within half a square

– all graph points plotted accurately using a sharp pencil, as a small cross or a small dot in a circle, with

the intersection of the cross or centre of the dot exactly on the required point

– the plotted points of a graph connected with a clear, sharp and unbroken line, either as a line of best fit,

a smooth curve or with ruled straight lines joining the points

– no extrapolation of graph lines unless this can be assumed from the data

– all bars on a bar chart or histogram plotted accurately, with clear, unbroken lines that are drawn with a

sharp pencil and ruler.

When using the light microscope and photomicrographs, students should be able to:

• make drawings, using a sharp pencil to give finely drawn lines that are clear and unbroken

• make drawings that use most of the available space and show all the features observed in the specimen,

with no shading

• organise comparative observations, showing differences and similarities between specimens.

Analysis, conclusions and evaluation

Interpreting data and observations

Within an investigation, students should be able to:

• calculate an answer with the correct number of significant figures using quantitative results or data provided

• use a graph to find unknown values

• estimate the concentrations of unknown solutions from qualitative results

• identify the contents of unknown solutions using biological molecule tests

• identify anomalous results and suggest how to deal with anomalies

• describe patterns and trends using the data provided in tables and graphs

• evaluate the confidence with which conclusions might be made.

When using the light microscope and photomicrographs, candidates should be able to:

• calculate an answer with the correct number of significant figures using quantitative results or data provided

• compare observable features of specimens of biological material including similarities and differences

between specimens on a microscope slide and specimens in photomicrographs.

Drawing conclusions

From results, observations or information provided, students should be able to:

• summarise the main conclusions

• state and explain whether a hypothesis is supported

• make predictions from the patterns and trends in data

• suggest explanations for observations, results, patterns, trends and conclusions.

Identifying sources of error and suggesting improvements

Within an investigation and when using the light microscope and photomicrographs, students should be able

to:

• identify systematic or random errors in an investigation, understanding that systematic errors may not affect

the trend in results whereas a random error may affect the trend

• identify the main sources of error in a particular investigation

• suggest improvements to a procedure that will increase the accuracy of the observations or measurements,

including:

– using a more effective method to standardise relevant variables

– using a more accurate method of measuring the dependent variable

– using smaller intervals for the values of the independent variable

– collecting replicate measurements so that a mean can be calculated

• suggest how to extend the investigation to answer a new question, for example by investigating a different

independent variable or applying the method to a new context

• describe clearly, in words or diagrams, improvements to the procedure or modifications to extend the

investigation.

Grade 12:

Planning

Defining the problem

Using the context provided, students should be able to:

• state a relevant prediction, either in words or in the form of a sketch graph showing the expected result,

and link this to an underlying hypothesis

• identify the independent and dependent variables

• identify which key variables must be standardised in order to test a hypothesis. (Variables expected to have

a minimal effect, such as variation between test-tubes of the same type, do not need to be standardised.)

Methods

Using the context provided, students should be able to:

• describe how to vary the independent variable

• describe how to measure the values of the independent and dependent variables accurately and to an

appropriate precision

• describe how to standardise each of the other key variables

• describe, where appropriate, suitable volumes and concentrations of reagents. Concentrations may be

specified in % (w/v), or mol dm–3

• describe how different concentrations would be prepared by serial dilution or proportional dilution

• describe appropriate control experiments

• describe, in a logical sequence, the steps involved in the procedure, including how to use the apparatus to

collect results

• describe how the quality of results can be assessed by considering:

– the occurrence of anomalous results

– the spread of results including the use of standard deviation, standard error and/or 95% confidence

intervals (95% CI).

• describe how to assess the validity of the results by considering both the accuracy of the measurements

and the repeatability of the results

• prepare a simple risk assessment of their plans, taking into account the severity of any hazards and the

probability that a problem could occur

• describe the precautions that would need to be taken to minimise risks where possible.

Analysis, conclusions and evaluation

Dealing with data

From provided data, students should be able to:

• use tables and graphs to show the key points in quantitative data

• sketch or draw suitable graphs, displaying the independent variable on the x-axis and the dependent

variable on the y-axis including, where required, confidence limit error bars

• decide which calculations are necessary in order to draw conclusions

• carry out appropriate calculations to simplify or explain data, including means, percentages and rates of

change

• carry out calculations in order to compare data, including percentage gain or loss

• use values of standard deviation or standard error, or graphs with standard error bars, to determine

whether differences in mean values are likely to be statistically significant

• choose and carry out statistical tests (limited to those described in the Mathematical requirements section

of the syllabus) appropriate to the type of data collected and justify use of these tests

• state a null hypothesis for a statistical test

• recognise the different types of variable and the different types of data presented, as shown in the table

below.

Type of variable Type of data

Qualitative

categoric nominal, i.e. values or observations belonging to it can be sorted according to category, e.g. colour of flowers

ordered ordinal, where values can be placed in an order or rank and the interval between them may not be equal, e.g. the order in which test-tubes containing starch and iodine become colourless after adding amylase

Quantitative continuous, which can have any value within a specific range, e.g. body mass, leaf length

Conclusions

Students should be able to:

• summarise the main conclusions from the results

• identify key points of the raw data and processed data, including graphs and statistical test results

• discuss the extent to which a given hypothesis is supported by experimental data and the strengths and

weaknesses of the evidence

• give detailed scientific explanations of the conclusions

• make further predictions and hypotheses based on the conclusions.

Evaluation

Students should be able to:

• identify anomalous values in a table or graph of data and suggest how to deal with anomalies

• suggest possible explanations for anomalous readings

• assess whether the results have been replicated sufficiently

• assess whether the range of values of the independent variable and the intervals between the values were

appropriate

• assess whether the method of measuring is appropriate for the dependent variable

• assess the extent to which selected variables have been effectively controlled

• make informed judgements about:

– the validity of the investigation

– the extent to which the data can be used to test the hypothesis

– how much confidence can be put in the conclusions

• suggest how an investigation could be improved to increase confidence in the results.

Specific experiments that are recommended to be practically investigated while teaching the relevant theoretical topics to students:

Experiment 1: Rate of an Enzyme Controlled Reaction

Experiment 2: Calculating Mitotic Index using Plant Cells

Experiment 3: Investigating Water Potential

Experiment 4: Investigating Cell Membrane Permeability

Experiment 5: Chromatography of Photosynthetic Pigments

Experiment 6: Dehydrogenase Activity in Chloroplasts

Experiment 7: Respiration in Single Celled Organisms

Experiment 8: Investigating Simple Animal Responses

Experiment 9: Measuring Concentration of Glucose using a Calibration Curve

Experiment 10: Effect of Different Variables on Species Distribution

Experiment 11: Effect of Caffeine on Heart Rate in Daphnia

Experiment 12: Investigating plant mineral deficiencies

Experiment 13: Antimicrobial properties of plants

Experiment 14: Ecology of a habitat

Experiment 15: Photosynthesis and the Hill reaction

Experiment 16: Separating DNA fragments - gel electrophoresis

Experiment 17: Effect of different antibiotics

Experiment 18: Investigate rate of respiration

Experiment 19: Measure effects of exercise

Experiment 20: Habituation to a stimulus

Experiment 21: Sucrose concentration and pollen tube growth

Experiment 22: Environmental conditions and water uptake

Experiment 23: Different wavelengths of light and photosynthesis

Experiment 24: Rate of growth of microorganisms in culture

Experiment 25: Gibberellin on the production of Amylase

Experiment 26: Effect of different sampling methods on estimates of the size of a population

Experiment 27: Effect of one abiotic factor on species distribution and morphology

 

 

 

Detailed Learning Objectives

 

 

Students should be able to:

Understand and express scientific ideas using the below terms:

- True value: the value that would be obtained in an ideal measurement

- Measurement error: the difference between a measured value and the true value of a quantity

- Accuracy: a measurement result is described as accurate if it is close to the true value

- Precision: how close the measured values of a quantity are to each other

- Repeatability: a measurement is repeatable if the same or similar result is obtained when the measurement is repeated under the same conditions, using the same method, within the same experiment

- Reproducibility: a measurement is reproducible if the same or similar result is obtained when the measurement is made under either different conditions or by a different method or in a different experiment

- Validity of experimental design: an experiment is valid if the experiment tests what it says it will test. The experiment must be a fair test where only the independent variable and dependent variable may change, and controlled variables are kept constant

- Range: the maximum and minimum value of the independent or dependent variables

- Anomaly: an anomaly is a value in a set of results that appears to be outside the general pattern of the results, i.e. an extreme value that is either very high or very low in comparison to others

- Independent variables: independent variables are the variables that are changed in a scientific experiment by the scientist. Changing an independent variable may cause a change in the dependent variable

- Dependent variables: dependent variables are the variables that are observed or measured in a scientific experiment. Dependent variables may change based on changes made to the independent variables

• demonstrate knowledge of how to select and safely use techniques, apparatus and materials (including following a sequence of instructions where appropriate):

– identify apparatus from diagrams or descriptions

– draw, complete or label diagrams of apparatus

– use, or explain the use of, common techniques, apparatus and materials

– select the most appropriate apparatus or method for the task and justify the choice made

– describe and explain hazards and identify safety precautions

– describe and explain techniques used to ensure the accuracy of observations and data

• plan experiments and investigations:

– identify the independent variable and dependent variable

– describe how and explain why variables should be controlled

– suggest an appropriate number and range of values for the independent variable

– suggest the most appropriate apparatus or technique and justify the choice made

– describe experimental procedures

– identify risks and suggest appropriate safety precautions

– describe how to record the results of an experiment

– describe how to process the results of an experiment to form a conclusion or to evaluate a prediction

– make reasoned predictions of expected results

• make and record observations, measurements and estimates:

– take readings from apparatus (analogue and digital) or from diagrams of apparatus

– take readings with appropriate precision, reading to the nearest half-scale division where required

– correct for zero errors where required

– make observations, measurements or estimates that are in agreement with expected results or values

– take sufficient observations or measurements

– repeat observations or measurements where appropriate

– record qualitative observations from tests

– record observations and measurements systematically, for example in a suitable table, to an appropriate degree of precision and using appropriate units

• interpret and evaluate experimental observations and data:

– process data, including for use in further calculations or for graph plotting, using a calculator as appropriate

– present data graphically, including the use of best-fit lines where appropriate

– analyse and interpret observations and data, including data presented graphically

– use interpolation and extrapolation graphically to determine a gradient or intercept

– form conclusions justified by reference to observations and data and with appropriate explanation

– evaluate the quality of observations and data, identifying any anomalous results and taking appropriate action

– comment on and explain whether results are equal within the limits of experimental accuracy (assumed to be ± 10% at this level of study)

• evaluate methods and suggest possible improvements:

– evaluate experimental arrangements, methods and techniques, including the control of variables

– identify sources of error, including measurement error, random error and systematic error

– identify possible causes of uncertainty in data or in a conclusion

– suggest possible improvements to the apparatus, experimental arrangements, methods or techniques