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  • 1. CCEA Exemplar Scheme of Work: GCE Biology A2 2: Biochemistry, Genetics and Evolutionary Trends 1
  • 2. CCEA Exemplar Scheme of Work: GCE Biology Unit A2 2: Biochemistry, Genetics and Evolutionary Trends Specification Section 5.1: Respiration Time required: 1/2 weeks Based on approx 4.5 hours teaching time per week 5.1 Respiration (Guidance only) Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.1.1 Recognise the nature and • Show the structure of ATP on a simple diagram • LINK – 1.1.3 Recognise the function of ATP which shows the component structures – occurrence, structure and function of adenine, ribose and phosphate. carbohydrates • Explain the conversion of ATP to ADP and the consequent release of energy from the final phosphate high energy bond within the structure. Link this to the process of respiration that it is the process by which cells release energy through the utilisation of the energy stored in ATP. • Conversion of ATP to ADP. Give pupils various examples where ATP is used in active • LINK – 2.1.2 Understand the transport e.g. mineral uptake, absorption of features of exchange surfaces which amino acids in the proximal convoluted tubule aid passive and active transport of the kidney nephron. • LINK – 4.1.2 Describe the function of the nephron 2
  • 3. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.1.2 Understand glycolysis • Definition of glycolysis – the ‘splitting of sugar’. • Underline that glycolysis is a common process to both aerobic and anaerobic respiration. Idea shower the features of aerobic and anaerobic respiration, based on GCSE knowledge. • Using diagrams of cell ultrastructure show that glycolysis takes place in the cell cytoplasm. • Use a flow diagram, possibly a cut and stick • LINK – 1.5.3 Understand the exercise, to show the conversion process of structure and function of eukaryotic glucose to the final pyruvate 3C structure. cell components • Highlight that there is only a small yield of ATP (2) from glycolysis - at this stage introduce a summary table for ATP yield which can be filled in as the topic progresses. 3
  • 4. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.1.3 Understand aerobic respiration • Show pupils the equation for aerobic respiration and ask them to explain the inputs, process and outputs. Their explanation can then be expanded to A2 level following the process below. Highlight the relevance of the equation and at all times refer back to the equation throughout the explanation. • Show a composite diagram of all 3 reactions i.e. glycolysis, Krebs cycle and electron transport • www.qcc.cuny.edu/BiologicalScie chain to show that each reaction is linked to the nces/Faculty/DMeyer/respiratio next. n.html • Design a flow diagram to show the stages of • programs.northlandcollege.edu/bi glycolysis enhanced with the use of the ology/Biology1111/animations/gl animation. Note enzyme activity. ycolysis.html • Demonstrate that the product of glycolysis (pyruvate) is used in the Krebs cycle via the ‘Link Reaction’. • Add in to the initial diagram the location of each reaction in the mitochondria. 4
  • 5. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.1.4 Understand anaerobic respiration • Show pupils the equation for anaerobic respiration and ask them to explain the inputs, process and outputs. Their explanation can then be expanded to A2 level following the process below. Highlight the relevance of the equation and at all times refer back to the equation throughout the explanation. • State the main defining feature of anaerobic respiration – that glycolysis occurs followed by • LINK – 1.2.1 Understand the further reactions which regenerate the co- structure of enzymes enzyme NAD+ • www.instruct1.cit.cornell.edu/Cou • Highlight that the net yield of ATP will be 2 rses/biomi290/MOVIES/GLYC since only glycolysis is occurring. OLYSIS.HTML • State that ethanol and carbon dioxide are produced in plants and microorganisms – relevance to production of beer and bread. • State that lactate is the product in animals – relevance to muscle cramp during exercise and ‘paying back your oxygen debt’. 5
  • 6. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.1.5 Understand Krebs cycle • Make pupils aware that in different textbooks that the Krebs cycle may be referred to as the citric acid cycle or TCA cycle. • Understand that the Krebs cycle is oxidative decarboxylation, in simple terms the removal of carbon atoms from carbon substrates. • Show the cycle as a circular diagram encompassing various carbon substrate molecules, producing NADH (+H+), FADH2 and ATP. Use the analogy of a ferris wheel – the seats representing the carbon substrate molecules with differing numbers of carbon atoms. • Produce another summary table of the net yield • www.wiley.com/legacy/college/b of co-factors – NADH +H+ etc. oyer/0470003790/animations/tca /tca.htm • Use animations to enhance diagrams. • www.wiley.com/college/pratt/04 • Mention the use of different respiratory 71393878/student/animations/citr substrates – carbohydrate, protein and fat and ic_acid_cycle/index.html the consequential energy release – this can be inserted into the summary table previously mentioned as a method of structuring revision. 6
  • 7. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.1.6 Understand the electron • The products of the Krebs cycle – NADH + transport chain H+ and flavoproteins (FADH2) enter the electron transport chain. This is the reaction during which the greatest net yield of ATP is produced. • Explain the electron transport chain in terms of carriers which pass on electrons. These carriers are arranged at progressively lower energy levels – as in a staircase. As each energy level is reached, excess energy is released. This process can be demonstrated using a tennis ball, pupils are arranged in descending order of the electron carriers and the tennis ball is then passed between them – other pupils can then be used to represent the release of energy bound in ATP. • Draw the electron transport chain as a simple staircase diagram – mark on this diagram the points at which ATP is synthesised, the final hydrogen acceptor and the net yield of ATP for NADH (+H+) or reduced flavoprotein (FADH2). Insert these values into the ATP yield summary table. • Emphasise that oxygen is the final hydrogen acceptor in the electron transport chain, it combines with oxygen to form water – highlight the significance of this step with reference to the equation, water is a product of respiration. • Use animations to consolidate information. • www.brookscole.com/chemistry_ d/templates/student_resources/s 7
  • 8. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) hared_resources/animations/oxid ative/oxidativephosphorylation.ht ml • www.wiley.com/legacy/college/b oyer/0470003790/animations/elec tron_transport/electron_transport. htm • www.highered.mcgraw- hill.com/sites/0072437316/studen t_view0/chapter9/animations.htm l# 5.1.7 Compare aerobic and anaerobic • Summary table of aerobic and anaerobic respiration respiration – stages involved, substrates involved, products produced; emphasis on larger yield of ATP from aerobic than anaerobic respiration. • The significance of anaerobic respiration in the provision of ATP without the use of oxygen. • Provide relevant examples of the use of anaerobic respiration – training athletes, peat bogs etc. • Focus on anaerobic respiration as the production of lactic acid in animals – this results in an oxygen debt which is repaid after exercise – apply to context of training athletes. 8
  • 9. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.1.8 Understand the respiratory • RQ value as the ratio of carbon dioxide quotient produced to oxygen consumed in a respiring organism. • Demonstration of simple respirometer • Risk Assessment – KOH corrosive measuring oxygen consumption with potassium hydroxide present. Measuring the net difference between carbon dioxide production and oxygen consumption with no potassium hydroxide present. Determine carbon dioxide production and the RQ value. • Give various equations for pupils to work out the RQ value. Use RQ value found to determine respiratory substrate (e.g. carbohydrate = 1) and in detecting anaerobic respiration (greater than 1). 5.1.9 Practical Work • Simple Respirometer showing rate of • LINK – 2.1.8 Practical Work respiration/uptake of oxygen • Risk Assessment – KOH corrosive • Demonstrate the use of hydrogen acceptors using indicators e.g. methylene blue. 9
  • 10. CCEA Exemplar Scheme of Work: GCE Biology Unit A2 2: Biochemistry, Genetics and Evolutionary Trends Specification Section 5.2: Photosynthesis Time required: 1/2 weeks Based on approx 4.5 hours teaching time per week 5.2 Photosynthesis (Guidance only) Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.2.1 Describe the sites in the • Diagrams of the chloroplasts in increasing • LINK – 1.5.3 Eukaryotic Cell chloroplast where the reactions detail showing the structures involved and the Components of photosynthesis occur reactions which take place in situ. • Define the light-dependent stage and where it occurs in the chloroplast. • Define the light-independent stage, where it occurs in the chloroplast – refer to the past usage of the ‘dark’ reaction and Calvin cycle. 10
  • 11. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.2.2 Understand the light-dependent • Use the equation for photosynthesis as a stage of photosynthesis starting point for pupils to highlight the important factors involved in the process. This can also be used to come back to at different stages throughout the topic to reiterate and highlight specific points. Based on GCSE knowledge this will aid their understanding of this new material. • Introduce pupils to a simple diagram of the core principles of this reaction. • Use a cut and stick activity for pupils to make the light-dependent reaction – this should be done using the full extent of the page in order for pupils to visually understand the changes in energy levels involved. This technique can then • LINK – 2.1.5 Understand gas be further enhanced with the inclusion of more exchange in plants detail at later stages. • LINK – 2.1.8 Practical Work • Define terms used such as photophosphorylation by using the technique of breaking the word into its constituents; this enables pupils to think about the processes • www.highered.mcgraw- involved. hill.com/sites/0072437316/student • Emphasis on the products of this light- _view0/chapter10/animations.htm dependent stage – reduced NADP (NADPH) l and ATP which are then used in the light- • www.cst.cmich.edu/users/baile1re independent stage. /bio101fall/enzphoto/photoanima. • The dissociation of water to release oxygen. html • Refer back to the initial reference to the equation for photosynthesis, emphasise the following – light is required for the 11
  • 12. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) photoactivation of PSI, water is required to replace electrons in PSII through its dissociation to release oxygen. Highlight that the other events in the equation are mentioned in the light-independent stage. • Use animations to show pupils a moving visual image of the stages in the reaction. 5.2.3 Understand the light-independent • Begin with reference to the equation. stage in photosynthesis • Carbon dioxide fixation i.e. the use of carbon • LINK – 4.4.14 Explain the cycling of dioxide in the reactions of carbon substrates carbon in the ecosystem e.g. ribulose bisphosphate. • The use of NADPH, from the light-dependent stage, to reduce glycerate phosphate • The use of ATP, again from the light- dependent stage, to facilitate the reactions occurring. • Emphasis on the recycling nature of the • www.faculty.nl.edu/jste/calvin_cy substrates involved, they are not lost, simply cle.htm regenerated in the process. • .www.web.virginia.edu/gg_demo/ • The final stage of the synthesis of the C6 sugars. movies/figure18_12b.html • Animations to show the stages. 12
  • 13. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.2.4 Appreciate that light is absorbed • Begin with an emphasis on the fact that by chlorophyll and associated chlorophyll is not the only photosynthetic pigments pigment. Increase pupils understanding of this concept by showing them the light spectrum – there are several different wavelengths of light so it therefore makes sense that plants will do their best to optimise their usage of light available to them by having more than one pigment. • Use website to show absorption spectra and action spectrum. Highlight the difference between these two spectra – absorption spectra is the action of the pigments within plants, the action spectrum is the wavelengths of light. 13
  • 14. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.2.5 Understand the external factors • The rate of photosynthesis is measured by limiting the rate of photosynthesis carbon dioxide uptake or oxygen production as shown in the equation previously. • www.tomatosphere.org/EngManu • Define the terms gross and net photosynthesis al/activity9a.html and compensation point. Compensation point can be further examined using the web link. • Table to show external factors which could limit the rate of photosynthesis – let pupils develop these factors themselves. Use a case study scenario of a market gardener and pupils can put the factors into context. Include in the table information on each factor and an example of the graph which would be produced. 5.2.6 Practical Work • Refer to the use of the Audus apparatus. • LINK – 2.1.8 Practical Work • Paper chromatography of plant pigments to • LINK – 1.1.8 Practical Work illustrate the presence of more than one pigment present in plants. Include the calculation of Rf values. • Demonstrate the role of hydrogen acceptors using redox indicator such as DCPIP. 14
  • 15. CCEA Exemplar Scheme of Work: GCE Biology Unit A2 2: Biochemistry, Genetics and Evolutionary Trends Specification Section 5.3: DNA as the Genetic Code Time required: 2 weeks Based on approx 4.5 hours teaching time per week 5.3 DNA as the Genetic Code (Guidance only) Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.3.1 Understand the nature of the • Recall information from Module 1 that a gene • LINK – 1.1.6 Recognise the genetic code. is a sequence of bases on a strand of DNA. occurrence, structure and function of • The specific sequence of the bases will nucleic acids determine which amino acids join together to • LINK – 1.1.5 Recognise the form a polypeptide. occurrence, structure and function of • Animation of DNA structure. proteins • Introduce the concept of codes as a shortened • www.johnkyrk.com/DNAanatomy way of carrying a large volume of information .html e.g. Morse code. • Specify that the genetic code is a non- overlapping, degenerate code of three bases i.e. a codon. • Define the terms non-overlapping and degenerate. • Give examples of codons and the amino acid that they code for. 15
  • 16. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.3.2 Understand the process of • Explain transcription using the analogy of transcription in the synthesis of writing down information in order for it to be proteins. transferred from one location to another. • Explain transcription in the context of the writing down of the genetic information involving the unpairing of bases in one region of the DNA followed by the synthesis of a strand on mRNA which carries a triplet code sequence which is complementary to the DNA. • www.learn.genetics.utah.edu/unit Emphasise that the DNA is a template for the s/basics/transcribe mRNA, this is the messenger which allows the • www.library.thinkquest.org/20465 genetic info in the form of the triplet code to /g_DNATranscription.html be carried from one location in the cell to another. • Animation showing transcription. 16
  • 17. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.3.3 Understand the process of • Explain translation as the de-coding or ‘reading’ translation in the synthesis of of the triplet message on the mRNA. proteins. • The codon, 3 bases, has a natural complementary sequence of 3 bases, this is referred to as the anticodon. This set of 3 bases is attached to a specific tRNA molecule which carries and transfers a specific amino acid. Note that specificity of amino acid is determined by the sequence of the triplet code and anticodon as explained in 5.3.1. • The complementary triplets on mRNA and • LINK – 1.1.5 Recognise the tRNA will pair together in ribosomal sites occurrence, structure and function of (peptidyl and aminoacyl) – ribosomes situated proteins in the cell cytoplasm hence the need for mRNA • www.biostudio.com/demo_freema and tRNA. n_protein_synthesis.htm • When 2 amino acids are side by side, at the 2 • www.wisc- sites on the ribosome, a condensation reaction online.com/objects/index_tj.asp? will occur and a peptide bond will form objID=AP1302 between them. • Animation showing translation. • 1.1.6 Recognise the occurrence, structure and function of nucleic acids • Cut and stick exercise to show both transcription and translation on one page – highlighting the processes and their locations. • Outline the structure and function of tRNA and ribosomes. • 17
  • 18. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.3.4 Explain the one gene/one • Emphasise that one gene codes for a specific polypeptide theory. polypeptide - enzyme, hormone, antibody etc. This can be enhanced by demonstrating fictitious examples of base sequences leading to amino acid chains etc – emphasis on the • LINK – 1.2 Enzymes sequence of the bases determining the sequence of the amino acids and hence the polypeptide. • The importance of enzymes in controlling all cell reactions and metabolic pathways. 18
  • 19. CCEA Exemplar Scheme of Work: GCE Biology Unit A2 2: Biochemistry, Genetics and Evolutionary Trends Time required: 2 weeks Specification Section 5.4: Gene Technology Based on approx 4.5 hours teaching time per week (Guidance only) 5.4 Gene Technology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.4.1 Explain the stages involved in • Explain an overview of gene technology, its gene transfer uses, benefits and drawbacks. Use relevant examples to engage pupils e.g. ‘Dolly the sheep’, ‘Flavr Savr’ tomatoes, embryo technology, designer babies etc. • Explain the stages involved in gene technology as a flow diagram which can be expanded into fully detailed notes – obtaining donor DNA with use of enzymes, use of DNA probes, incorporation into donor genes using vectors, transformation of recipient cells and use of markers to check success of recipient cells. • Define all or any terms which pupils may find difficult, this is most easily done by developing a genetics vocabulary list which can be updated • www.present.udel.edu/biotech/rD as the topic progresses. NA.html • Explain why recipient cells are chosen e.g. rapid • www.pbs.org/wgbh/nova/genom life cycle etc. Show pictures of recipient cells e/sequencer.html# and pupils can use this as a visual tool for memory skills. 19
  • 20. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) • Use analogies to enhance explanation and link the information covered here to the theory previously covered in other modules, highlighting the fact that this topic involves the application of theory covered into industry etc. • Use animations. 5.4.2 Appreciate the range of • Highlight that micro organisms are used as substances produced by recipient organisms due to their rapid life cycle. genetically engineered micro • Detail the process of the production of the organisms important chemicals using a flow diagram, this puts the theory covered in 5.4.1 into the context of each chemical studied – insulin, human growth hormone, enzymes, adhesives, lung surfactant protein etc. • Highlight that this method of production is highly efficient and effective and also necessary in modern pharmaceuticals and medicine. • Where possible link the use of these products • highered.mcgraw- to the topics studied at AS and A2 to further hill.com/sites/0072437316/student place them into context e.g. lung surfactant _view0/chapter16/animations.htm links to Respiratory systems in mammals in l# 2.1.6 • Website 20
  • 21. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.4.3 Appreciate the role of transgenic • Definition of a transgenic organism. animals and plants • Possible topic for discussion and pupil research using topical issues – newspapers etc. • Table of examples of transgenic plants, brief description, their products, benefits, drawbacks etc. • Table of examples of transgenic animals, brief description, their products, benefits, drawbacks etc. • www.learner.org/channel/courses • Use newspaper articles and/or topical television /biology/units/gmo/images.html news reports or documentaries to inform pupils and to inspire interest in this field e.g. Channel 4 ‘Animal Farm’ 2007. • Website 21
  • 22. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.4.4 Explain gene therapy, showing an • This is an opportunity for pupils to research appreciation of advantages and this topic and present back information to the problems class – emphasis on advantages and disadvantages etc. • Define the need for gene therapy as a treatment for genetic disease caused by an absence of a gene or a faulty gene. • Treatment through the introduction of a functional gene to restore normal functioning e.g. treatment of CF through the use of an inhaler which contains lipid droplets each of which contains the functional gene to correct the CF condition. These droplets are inhaled into the lungs and the lipid droplet fuses with the lipid bi-layer of the membrane so releasing the functional gene into the lung cells. • Discuss and summarise the advantages and disadvantages of somatic cell replacement therapy. 22
  • 23. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.4.5 Understand genome sequencing • Define genome – the complete sequence of projects DNA on one set of chromosomes in diploid, eukaryotic organisms. Relate the sequence of DNA to the fact that it is the sequence of genes present as determined by the sequence of bases. Hence, the determination of the genetic code. • Look at the sequencing projects which have been undertaken to date via the web e.g. E.coli as the first organism to be fully sequenced etc. • LINK – 1.1.5 Recognise the Each group of pupils could be asked to occurrence, structure and function of research one of the listed organisms and report proteins back to the class on the details found. • Development of the fact that knowledge of the • www.genome.gov/25019879#GetC genetic code as discussed above, enables the D production of the structure of the proteins that • www.sumanasinc.com/webconten would be produced during expression of the t/anisamples/nonmajorsbiology/ genes. dnalibrary.html • Discussion of the Human Genome Project • www.dnalc.org/ddnalc/resources/ using the web address listed. animations.html • Highlight that the production of genome • www.dh.gov.uk/en/Publicationsa sequences enables a library to be produced ndstatistics/Publications/Publicat which details genetic disorders etc and will ionsPolicyAndGuidance/DH_4118 therefore support developments in gene 934 therapy, genetic testing, diagnosis and designer drugs. Give relevant examples which will support this theory e.g. Pre-implantation Genetic Diagnosis, breast cancer and CF treatment. 23
  • 24. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.4.6 Appreciate that the inactivation or • Discuss experimentation using animals, explain • www.en.wikipedia.org/wiki/Knoc replacement of genes facilitates that the true functioning of a gene can only be kout_mice the understanding of gene and determined when its effects are seen in a similar organism function. organism e.g. a mammal. The effects of the gene can be seen when the gene is removed, this allows the genes role in protein production and therefore metabolism to be assessed. The mouse is a useful organism to use for this diagnostic treatment – knockout mouse and knockin mouse (website). This technology is again useful in the development of genetic disorders and drug therapies e.g. Parkinson’s disease, arthritis and diabetes. 24
  • 25. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.4.7 Appreciate social, legal, ecological • This can involve pupil research and the staging and ethical issues regarding the of a debate-like class structure. Each pair of benefits and risks of gene pupils can be given an identity within this social technology debate and they then defend their position e.g. pharmaceutical company, Religious leader, animal rights campaigner, ecological campaigner etc. This will encourage them to research the issues involved and to develop a reasoned view on the subject. Develop a set of questions which you can ask and challenge the pupils which will encourage them to think • Summarise all points in a table of benefits and risks. • Guide pupils to consider the following; safety precautions, limitations of gene transfer, potential dangers of gene transfer and need for legislation. Give examples where applicable. 25
  • 26. CCEA Exemplar Scheme of Work: GCE Biology Unit A2 2: Biochemistry, Genetics and Evolutionary Trends Time required: 4 weeks Specification Section 5.5: Genes and Patterns of Inheritance Based on approx 4.5 hours teaching time per week (Guidance only) 5.5 Genes and Patterns of Inheritance Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.5.1 Understand the terms genotype • Provide pupils with definitions of these two and phenotype terms. • Use analogies to explain the difference between these terms – e.g. genotype is the genes, phenotype is the outward appearance as determined by the genotype and the environment etc. • Define homozygosity and heterozygosity – if appropriate remind pupils of homo and hetero as prefixes to other words which they may be more familiar with e.g. homologous chromosomes at GCSE. 5.5.2 Understand the relationship • Develop a vocabulary list of the definitions of between chromosomes, genes and each of the terms used. alleles • Enhance this list using diagrams of the structures involved and how they are all related • www.sciencenetlinks.com/interact to one another. ives/dna.swf • Animation to show the relationship between • www.biostudio.com/demo_freema the chromosome, DNA and allele. n_dna_coiling.htm 26
  • 27. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.5.3 Understand the inheritance of • Define various types of variation – show pupils traits showing discontinuous typical graphs of data and ask them to explain variation the results with regards to characteristics in • www.science.nhmccd.edu/biol/m plants and animals. onohybr/monhybr.html • Define monohybrid and dihybrid inheritance – • www.science.nhmccd.edu/biol/di mono means one and di- means two traits. hybrid/dihybrid.html • State Mendel’s first law of inheritance. • Explain dominance and recessiveness using examples and analogies. • State Mendel’s second law of inheritance and link both laws to the increase genetic diversity at meiosis, no two individuals are the same. • Work out various examples using the genetic diagram as a standard format – teach pupils • www.science.nhmccd.edu/biol/m how to display their work using a punnett onohybr/test.html square where applicable. • www.biologica.concord.org/webte • Teach pupils the test cross method of st1/web_labs_mendels_peas.htm determining the genotype of an unknown organism. • Use various examples to explain and enhance the theory e.g. monohybrid tall and short pea plants, codominance in flower colour, multiple alleles for blood groups and chicken combs, lethal alleles etc. Use the animations available to increase understanding. 27
  • 28. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.5.4 Understand sex determination • Define the difference between autosomes and and sex linkage sex chromosomes. • State the determination of sex in mammals through XX and XY – study different karyotype diagrams and ask pupils to identify the sex of the individual – this will revise previous knowledge. • Dominant and recessive characters can be sex linked – carried on the X chromosome e.g. Haemophilia, colour blindness etc. 5.5.5 Gene interaction • Explain what gene interaction is and give examples – the characteristics of both genes which affect each other e.g. sweet pea plant, 2 white flowered parents can produce purple and white flowered offspring. • Give examples of the inheritance of traits showing gene interaction e.g. sweet pea plants, chinchilla coat colour etc. 5.5.6 Understand the inheritance of • Definition of continuous variation using the traits showing continuous typical graph to explain any data. variation (polygenic inheritance) • In its most basic form polygenic inheritance means more genes therefore more phenotypes therefore continuous variation –organisms belong to neither one category or the other. • Emphasis on the environment as a contributing factor to continuous variation. 28
  • 29. CCEA Exemplar Scheme of Work: GCE Biology Unit A2 2: Biochemistry, Genetics and Evolutionary Trends Time required: 2/3 weeks Specification Section 5.6: Mechanism of Change Based on approx 4.5 hours teaching time per week (Guidance only) 5.6 Mechanism of Change Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.6.1 Understand the concept of the • Define the term gene pool – the total sum of gene pool the alleles of genotype and allele frequencies of a gene in a population at a given time. • Look at genotype frequencies. • Look at phenotype frequencies. • Allele frequencies. • Apply these terms to examples. 29
  • 30. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.6.2 Understand the Hardy-Weinberg • Vocabulary list. equation and apply it to calculate • Explain that the Hardy-Weinberg principle allele and genotype frequencies in allows us to predict numbers of expected an outbreeding population genotypes in a population. The principle tracks the proportion of two different alleles in the population. • State the Hardy-Weinberg equation – p2 + 2pq + q2 = 1 where the allele frequencies are denoted by p and q for the alleles A and a. • p2 represents the homozygous dominant condition. • 2pq represents the heterozygous condition. • q2 represents the homozygous recessive • www.ncbi.nlm.nih.gov/disease/E condition. VC.html • Use of the equation to calculate allele frequencies from various examples • The Hardy-Weinberg principle is the situation in which a genetic equilibrium is maintained and in which alleles combine randomly at fertilisation. • Summarise the conditions for the application of Hardy-Weinberg equilibrium in a table e.g. non- random mating as applied to wind pollinated grass flower; migration leading to gene flow – in the Amish population this gene flow is missing (website); mutations; natural selection as highlighted by Ptarmigan plumage moult and large finally population size. 30
  • 31. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) • Apply this theory to relevant examples and encourage pupils to apply this information to their general knowledge of the natural world. 31
  • 32. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.6.3 Understand the source and • Vocabulary list. maintenance of genetic variation • The heterozygote individual as that which is a reservoir of genetic variation within a population due to the fact it is the individual with 2 alleles of one gene. This condition maintains the occurrence of disadvantageous alleles in the population whereas the • www.ygyh.org homozygote recessive for this allele is eliminated due to the disadvantages delivered to the phenotype e.g. failure to reproduce. • Mutations as a source of variation in that a mutation leads to a change in structure or amount of DNA. This will then lead to the production of different proteins which will result in increased variation within the population; somatic cell mutations will affect the organisms phenotype and therefore their survival but will not influence evolution. Mutation can be further studied in terms of gene mutation which will lead to one individual characteristic changing and then chromosome mutation (aneuploidy and polyploidy) which will lead to the inheritance of the mutant characteristic by the offspring. Polyploidy organisms are often associated with extremely advantageous features such as size, hardiness, disease resistance etc, discuss and note the significance of this with regards to plant breeding for successful/desirable characteristics. 32
  • 33. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) • Mutagenic agents can be discussed with regards to pupil’s own knowledge – reference can be made to the Chernobyl disaster and the research carried out into the increased occurrence of Leukaemia in people who live close to electricity pylons. This can then lead into a table of the different mutagenic agents e.g. X-rays, UV light, Cyclamate – pupils will be able to relate some of these to experiences in real context (lead vests for nurses who carry out X-rays in hospitals). • Sexual reproduction is the basic method of maintaining variation due to cross fertilisation of gametes carrying different genetic information. 33
  • 34. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.6.4 Understand selection and its • Vocabulary list defining selection, polymorphic contribution to the maintenance and evolutionary change. of polymorphic populations and • Discuss natural selection in respect to Darwin evolutionary change in and build on their general knowledge and populations knowledge from GCSE. • Examples – natural selection as illustrated by antibiotic resistance in bacteria and Darwin’s finches etc. • Stabilising selection as illustrated by the length of hind legs in rabbits and birth weight in human babies. Include typical graph. • Directional selection as illustrated by peppered moth and ear length in hares. Include graph. • Polymorphic populations are used to investigate both types of selection mentioned above due to the occurrence of many different individuals. 34
  • 35. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.6.5 Understand the concept of • Definition of species. species and the process of • Ask pupils to think about why all birds are not speciation the same, why all frogs are not the same. This will encourage them to see that within one genus of animals/plants there are several different species each with its own defining characteristic. Possibly even introduce the research on the various different species of human being – Homo habilis, Homo neanderthalensis etc. • Types of speciation which occur – table format; sympatric speciation between 2 groups in the same environment; allopatric speciation due to geographical isolation as with Darwin’s finches/Tilapia in Kenyan lakes leads to genetic divergence. • Study genetic divergence as the product of reproductive isolating mechanisms which prevent the new mutations in the isolated group being transferred to the original group – behavioural isolation, ecological isolation, temporal isolation, mechanical isolation and hybrid isolation giving appropriate examples. • Significance of polyploidy in plant speciation e.g. Spartina species – the sterile hybrid would not be able to carry out normal meiosis hence reproductive isolation. 35
  • 36. CCEA Exemplar Scheme of Work: GCE Biology Unit A2 2: Biochemistry, Genetics and Evolutionary Trends Time required: 2 weeks Specification Section 5.7: Kingdom Plantae Based on approx 4.5 hours teaching time per week (Guidance only) 5.7 Kingdom Plantae Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.7.1 Describe the form (level of • Provide pupils with flow diagram showing the • LINK – 2.3.8 Appreciate the 5 organisation) and life cycle in classification of Kingdom Plantae into different kingdom system of classification Division Bryophyta divisions and classes etc. Give various • LINK – 2.3.6 Understand the other examples of the organisms belonging to these taxa within which species can be divisions to provide pupils with a relevant link grouped to the theory. • Bring in a sample of the specimen e.g. moss and use it in an idea showering session focusing on the form, differentiation, features, structures etc. Introduce a diagram of the moss and use this to introduce technical names e.g. gametophyte, archaegonium and antheridium etc. • Provide pupils with a vocabulary list defining the scientific terms for the structures and develop a memory scheme for remembering the structures and their functions. • Table on form of Bryophyta. Emphasise the nature of the structure and its function and the role it plays in alternation of generations. 36
  • 37. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) • Life cycle displayed as a diagram using labels and pictures of structures involved in each stage. Colour code the sections of the sporophyte and gametophyte to effectively show the alternation of generations. Emphasise the importance of water for the transfer of sperm; spores formed by meiosis; gametes by mitosis. 37
  • 38. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.7.2 Describe the form (level of • Definition of Tracheophyta as multicellular • LINK – 2.1.13 Understand the organisation) and life cycle in plants with vascular system divided into 2 sub- movement of water (and dissolved Division Tracheophyta divisions – Pteridophytes and Spermatophytes. ions) through xylem • Provide classroom specimens of Pteridophytes • LINK – 2.1.14 Understand the and Spermatophytes and identify features and translocation of organic solutes structures. through phloem • Show pupils pictures of examples. • Introduce diagrams of specimens and label the structures – providing a vocabulary list where appropriate to aid understanding e.g. prothallus etc. Highlight that spermatophytes are more complex and advanced as they are not dependent upon water for reproduction – they produce pollen instead of spores. • Life cycle diagrams as with Bryophyta – colour coded to show alternation of generations etc. Emphasise the sporophyte is dominant over the gametophyte, spores produced by meiosis, gametes by mitosis. 5.7.3 Compare the divisions of Plantae • Repetition of flow diagram to highlight classification. • Review of features studied in each specimen. • Place these observations and notes into a table which details the characteristics and specific features of each division. • Highlight the increasing level of complexity and level of organisation from Bryophyta to Pteriodophyta to Spermatophyta. 38
  • 39. CCEA Exemplar Scheme of Work: GCE Biology Unit A2 2: Biochemistry, Genetics and Evolutionary Trends Specification Section 5.8: Kingdom Animalia Time required: 2 weeks Based on approx 4.5 hours teaching time per week 5.8 Kingdom Animalia (Guidance only) Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.8.1 Describe the body form and • Flow diagram showing classification of animals feeding in Phylum Cnidaria into phylum etc. • Highlight that animals are divided into phyla while plants are classified into divisions. • Develop a reference page for this topic which will include diagrams of radial and bilateral symmetry in body form; diploblastic/triploblastic; ectoderm; endoderm; mesoglea etc. and a vocabulary list to detail and explain such terminology as coelomate and aceolomate. • Concentrate on Phylum Cnidaria as radially symmetrical, diploblastic animals with little • LINK – 1.1.6 Understand the differentiation e.g. Hydra. Give diagram of mechanisms by which substances Hydra highlighting the body features (mesoglea, move across membranes hydrostatic skeleton etc.) and providing pupils with the opportunity to relate the structures present to the feeding habits and life cycle of the Hydra. 39
  • 40. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) • Emphasise that initial digestion is extracellular with the final phase intracellular by endocytosis. Encourage pupils to understand the use of tentacles etc in the feeding process. This could be enhanced using video clips from such T.V. documentaries as the ‘Blue Planet’. 40
  • 41. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.8.2 Understand the body form and • Platyhelminthes as triploblastic, acoelomate feeding in Phylum animals showing tissue differentiation e.g. Platyhelminthes Planarian. • Show pupils diagrams of the body structure of Planarian from external views and also transverse and longitudinal sections with labels. • Show pupils pictures of Planarian to link the diagrammatic representation to ‘real life’ • Introduce some outside interest with reference to the parasitic Platyhelminthes such as Liver Fluke etc. • Emphasise non-cellular mesoglea from Phylum Cnidaria becomes the cellular mesoderm which supports the body hence the organism retains its shape at all times unlike the jelly-like Cnidaria. • Differentiation in feeding habits from detritivores to active predators. Primitive digestive system – 1 opening to body with simple gut running throughout the body. Most of the digestive process is carried out intracellularly. • Direct pupils thought processes towards realising that there is an increase in complexity between the 2 phyla studied so far. • At this stage start developing a summary table which focuses on the main features of each Phyla – this will guide thought processes to make links between Phyla and will also aid the learning process. 41
  • 42. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.8.3 Describe the body form and • Annelida as triploblastic animals with a body feeding in Phylum Annelida cavity and tissue differentiation. • Highlight the following – first animal so far to have a body cavity and true tissue differentiation – increasing complexity. Encourage pupils to suggest reasons for this body cavity and tissue differentiation and to predict the feeding habits of the annelids. • Introduce the example of the earthworm using a diagram clearly labelled with defining features. • From this diagram move on to discuss body form – labelling the 3 body layers and the coelom. Highlight the well differentiated digestive system etc. • Note the bilateral symmetry and the segmentation of the body form – extrapolate to discuss other segmentation in other animals and this can be linked to the process of evolution from one common ancestor. Note that segmentation provides a hydrostatic skeleton for movement. Show a video clip of earthworm movement to explain how this hydrostatic skeleton works – again a good source would be ‘Life on Earth’ etc. • Highlight that earthworms are detritivores with a specialised gut and extracellular digestion. 42
  • 43. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) 5.8.4 Describe the body from and • Idea shower names of organisms that pupils feeding in Phylum Chordata think are chordates, from these initial ideas direct pupils to idea shower the characteristics of body form and feeding of the animals they have suggested. Encourage them to use the vocabulary introduced in this topic and try to reach a final stage of developing a few sentences to describe Chordates as has been done for them with other Phyla studied. • Chordates as triploblastic, coelomate animals with the defining feature of an internal skeleton using any example of a small mammal - mouse, rat etc. • Detail on form should focus on the variety of systems present due to complex differentiation of tissues. The nature of these systems means that chordates are bilaterally symmetrical, segmented and at some stage of development have a post-anal tail – show pictures of the human foetus in early stages of development when a small tail is evident to generate interest. • Defining feature of the internal skeleton is the stiff dorsal rod which gives the body structure and therefore a true back and front unlike Phylum Cnidaria. This skeleton is made from jointed calcified bones. Encourage pupils to make comparisons between the Phyla studied and this will enable them to remember the features of each. 43
  • 44. CCEA Exemplar Scheme of Work: GCE Biology Spec Ref Learning Outcomes Teaching Strategies Additional Notes (Resources, risk assessment, practical) • Discuss the variation in feeding habits – the differentiation in systems and complexity in body form enables chordates to be active predators, omnivores or herbivores. • Look at the mammalian digestive system as a sequence of well developed specialised regions where structure and function are closely linked as previously studied. Highlight that digestion is extracellular in the spaces within the system e.g. stomach and duodenum. • Finish by completing the summary table linking the features together and highlighting the increase in complexity for each Phyla and the consequences that has on feeding and lifestyle for organisms within that classification. Throughout the topic encourage pupils to think of their own examples as this will aid their learning process. 5.8.5 Practical Work • Study appropriate living and preserved specimens, prepared slides and photographs. 44