teaching scheme - a2 context approach

7/30/2019 Teaching Scheme - A2 Context Approach

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GCE A2 Biology Teaching Scheme (contextapproach)


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A2 Teaching scheme

This teaching scheme is based on the context approach.

It is a 30-week scheme, assuming making a start on A2 during the last four weeks of Year 12.

Both teaching schemes, context and concept, start with ecological topics from Unit 4, includingpractical ecology, as this may be an appropriate time of year for Centres to introduce these parts ofthe specification.

It is suggested that the Individual Investigation for Unit 6 takes the equivalent of two weeks ofnormal lesson and homework time. This should be incorporated into the scheme, as appropriate, bythe Centre.

The page numbers (*) refer to the Edexcel A2 Biology Students Book (Ann Fullick).

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Year 12

Last 4 weeks of the summer term making a start on A2

Week

number

Content of lessons Specification

references

Page

numbers (*)

Unit 4 Topic 5: On the wild side

31 The effect of biotic and abiotic factors on the numbers anddistribution of organisms in a habitat; how the concept ofniche accounts for the distribution and abundance oforganisms in a habitat; the concept of succession leading to aclimax community.

10, 12, 13 18 - 33

32 How to carry out a study on the ecology of a habitat toproduce valid and reliable data (including the use ofquadrats and transects to assess abundance and distribution

of organisms and the measurement of abiotic factors, e.g.solar energy input, climate, topography, oxygen availabilityand edaphic factors).

11

33 The causes of global warming including the role ofgreenhouse gases (carbon dioxide and methane, CH4) in thegreenhouse effect; analysis and interpretation of differenttypes of evidence for global warming and its causes(including records of carbon dioxide levels, temperaturerecords, pollen in peat bogs and dendrochronology),recognising correlations and causal relationships; how datacan be extrapolated to make predictions, their use in models

of future global warming and the limitations of these models.

14, 18, 19 38 - 47

34 The way in which scientific conclusions about controversialissues, such as what actions should be taken to reduce globalwarming, or the degree to which humans are affecting globalwarming, can sometimes depends on who is reaching theconclusions; the effects of global warming (risingtemperature, changing rainfall patterns and changes inseasonal cycles) on plants and animals (distribution ofspecies, development and life cycles).

15, 20 48 - 53

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Year 13

Weeknumber

Content of lessons Specificationreferences

Pagenumbers (*)

Unit 4 Topic 5: On the wild side (continued)

1 The effect of increasing temperature on the rate of enzymeactivity in plants, animals and microorganisms.How to investigate the effects of temperature on thedevelopment of organisms (e.g. seedling growth rate, brineshrimp hatch rates).

16, 17 50

2 The overall reaction of photosynthesis as requiring energy fromlight to split apart the strong bonds in water molecules, storingthe hydrogen in a fuel (glucose) by combining it with carbondioxide and releasing oxygen into the atmosphere; howphosphorylation of ADP requires energy and how hydrolysis ofATP provides an immediate supply of energy for biological

processes.

3, 5 10 - 11

3 The light-dependent reactions of photosynthesis, including howlight energy is trapped by exciting electrons in chlorophyll andthe role of these electrons in generating ATP, reducing NADPand producing oxygen through the photolysis of water.

4 12 - 16

4 The light-independent reactions of photosynthesis as thereduction of carbon dioxide using the products of the light-dependent reactions (carbon dioxide fixation in the Calvincycle, the role of GP, GALP, RuBP and RUBISCO); the productsare simple sugars which are used by plants, animals and otherorganisms in respiration and the synthesis of new biologicalmolecules (including polysaccharides, amino acids, lipids and

nucleic acids); the structure of chloroplasts in relation to theirrole in photosynthesis.

2, 6 16 - 17

5 Calculations of net primary productivity and the relationshipbetween gross primary productivity, net primary productivityand plant respiration; calculations to determine the efficiencyof energy transfers between trophic levels; how anunderstanding of the carbon cycle can lead to methods that canhelp to reduce atmospheric levels of carbon dioxide (includingthe use of biofuels and reforestation).

7, 8, 9 34 - 37

6 How evolution (a change in the allele frequency) can comeabout through gene mutation and natural selection; the role of

the scientific community in validating new evidence (includingmolecular biology, e.g. DNA, proteomics) supporting theaccepted scientific theory of evolution (scientific journals, thepeer review process, scientific conferences); how reproductiveisolation can lead to speciation.

21, 22, 23 54 - 61

Unit 4 Topic 6: Infection, immunity and forensics

7 How to determine the time of death of a mammal by examiningthe extent of decomposition, stage of succession, forensicentomology body temperature and degree of musclecontraction; the role of microorganisms in the decomposition of

organic matter and the recycling of carbon.

9, 20 66 - 71

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8 How DNA profiling is used for identification and determininggenetic relationships between organisms (plants and animals).How DNA can be amplified using the polymerase chain reaction(PCR); how gel electrophoresis can be used to separate DNAfragments of different length.

5, 6, 7 78 - 81

9 The structure of bacteria and viruses; how bacterial and viralinfectious diseases have a sequence of symptoms which mayresult in death, including diseases caused by Mycobacteriumtuberculosis (TB) and Human Immunodeficiency Virus (HIV).

8, 11 82 - 91

10 The non-specific responses of the body to infection, includinginflammation, lysozyme action, interferon, phagocytosis; therole of antigens and antibodies in the bodys immune response,including the involvement of plasma cells, macrophages andantigen-presenting cells; the roles of B cells (including Bmemory and B effector cells) and T cells (T helper, T killer andT memory cells) in the bodys immune response.

12, 13, 14 96 - 103

11 The process of protein synthesis (transcription, translation,messenger RNA, transfer RNA, ribosomes and the role of start

and stop codons) and the roles of the template (antisense) DNAstrand in transcription, codons on messenger RNA, anticodonson transfer RNA; the nature of the genetic code (triplet code,non-overlapping and degenerate); how one gene can give rise tomore than one protein through post-transcriptional changes tomessenger RNA.

2, 3, 4 72 - 77

12 The major routes pathogens may take when entering the body,and the role of barriers in protecting the body from infection,including the roles of skin, stomach acid, gut and skin flora;how individuals may develop natural immunity (natural,artificial, active, passive).

10, 15 92 95and

116 - 123

13 How the theory of an evolutionary race between pathogens

and their hosts is supported by the evasion mechanisms asshown by Human Immunodeficiency Virus (HIV) andMycobacterium tuberculosis (TB); differences betweenbacteriostatic and bactericidal antibiotics; how anunderstanding of the contributory causes of hospital acquiredinfections have led to codes of practice relating to antibioticprescription and hospital practice relating to infectionprevention and control.How to investigate the effect of different antibiotics onbacteria.

16, 17, 18, 19 104 111

and116 - 123

Unit 5 Topic 7: Run for your life

14 The way in which muscles, tendons, the skeleton and ligamentsinteract to enable movement, including antagonistic musclepairs, extensors and flexors; the contraction of skeletal musclein terms of the sliding filament theory, including the role ofactin, myosin, troponin, tropomyosin, calcium ions (Ca2+), ATPand ATPase.

3, 4 142 143and

148 - 151

15 The overall reaction of aerobic respiration as splitting of therespiratory substrate (e.g. glucose) to release carbon dioxideand reuniting of hydrogen with atmospheric oxygen with therelease of a large amount of energy; how phosphorylation of

ADP requires energy and how hydrolysis of ATP provides an

5, 6, 7, 8 128 - 135

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accessible supply of energy for biological processes; the roles ofglycolysis in aerobic and anaerobic respiration, including thephosphorylation of hexoses, the production of ATP, reducedcoenzyme and pyruvic acid (details of intermediate stages andcompounds are not required).Describe how to investigate rate of respiration practically.

16 The role of the Krebs cycle in the complete oxidation of glucoseand formation of carbon dioxide (CO2), ATP, reduced NAD andreduced FAD (names of other compounds are not required) andthat respiration is a many-stepped process with each stepcontrolled and catalysed by a specific intracellular enzyme; thesynthesis of ATP by oxidative phosphorylation associated withthe electron transport chain in mitochondria, including the roleof chemiosmosis and ATPase; the fate of lactate after a periodof anaerobic respiration in animals.

9, 10 ,11 136 141and

133 - 134

17 Cardiac muscle is myogenic; the normal electrical activity ofthe heart, including the roles of the sinoatrial node (SAN), theatrioventricular node (AVN) and the bundle of His, and how the

use of electrocardiograms (ECGs) can aid the diagnosis ofcardiovascular disease (CVD) and other heart conditions.

12 152 - 153

18 How variations in ventilation and cardiac output enable rapiddelivery of oxygen to tissues and the removal of carbon dioxidefrom them, including how the heart rate and ventilation rateare controlled and the roles of the cardiovascular controlcentre and the ventilation centre.How to investigate the effects of exercise on tidal volume andbreathing rate using data from spirometer traces.

13, 14 154 - 161

19 The structure of a muscle fibre and the structural andphysiological differences between fast and slow twitch musclefibres; the principle of negative feedback in maintaining

systems within narrow limits.

2, 15 144 - 147

20 The concept of homeostasis and its importance in maintainingthe body in a state of dynamic equilibrium during exercise,including the role of the hypothalamus and the mechanisms ofthermoregulation; analysis and interpretation of data onpossible disadvantages of exercising too much (wear and tear onjoints, suppression of the immune system) and exercising toolittle (increased risk of obesity, coronary heart disease (CHD)and diabetes), recognising correlation and causal relationships.

16, 18 162 - 174

21 How medical technology, including the use of keyhole surgeryand prostheses, is enabling those with injuries and disabilities

to participate in sports, e.g. cruciate ligament repair usingkeyhole surgery and knee joint replacement using prosthetics;two ethical positions relating to whether the use ofperformance-enhancing substances by athletes is acceptable;how genes can be switched on and off by DNA transcriptionfactors including hormones.

17, 19, 20 175 - 183

Unit 5 Topic 8: Grey matter

22 The structure and function of sensory, relay and motorneurones, including the role of Schwann cells and myelination;how the nervous systems of organisms can cause effectors to

respond, as exemplified by pupil contraction and dilation.

3, 7 198 199and218

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23 The mechanism of conduction of a nerve impulse (actionpotential) along an axon, including changes in membranepermeability to sodium and potassium ions and the role of thenodes of Ranvier; how flowering plants detect light usingphotoreceptors and how they respond to environmental cues.

2, 4 200 206and

188 - 193

24 The structure and function of synapses, including the role ofneurotransmitters, including acetylcholine; how the nervoussystems of organisms can detect stimuli with reference to rodsin the retina of mammals, the roles of rhodopsin, opsin, retinal,sodium ions, cation channels and hyperpolarisation of rod cellsin forming action potentials in the optic neurones.

5, 6 207 - 217

25 Comparisons between the mechanisms of coordination in plantsand animals, i.e. nervous and hormonal, including the role ofIAA in phototropism (details of individual mammalian hormonesare not required); the location and functions of the regions ofthe human brains cerebral hemispheres (ability to see, think,learn and feel emotions), hypothalamus (thermoregulate),cerebellum (coordinate movement) and medulla oblongata

(control the heartbeat).

8, 9 194 197and

219 - 221

26 The use of magnetic resonance imaging (MRI), functionalmagnetic resonance imaging (fMRI) and computed tomography(CT) scans in medical diagnosis and investigating brain structureand function; discussion of whether there exists a criticalwindow within which humans must be exposed to particularstimuli if they are to develop their visual capacities to the full.

10, 11 223 - 228

27 How animals, including humans, can learn by habituation; therole animal models have played in developing explanations ofhuman brain development and function including Hubel andWiesels experiments with monkeys and kittens; discussion ofthe moral and ethical issues relating to the use of animals in

medical research from two ethical standpoints.Describe how to investigate habituation to a stimulus.

12, 14, 15, 16 229 - 231

28 How imbalances in certain naturally occurring brain chemicalscan contribute to ill health (e.g. dopamine in Parkinsonsdisease and serotonin in depression) and to the development ofnew drugs; the effects of drugs on synaptic transmissions,including the use of L-Dopa in the treatment of Parkinsonsdisease and the action of MDMA in ecstasy.

17, 18 242 - 247

29 Discussion about how the outcomes of the Human GenomeProject are being used in the development of new drugs and thesocial, moral and ethical issues this raises; how drugs can be

produced using genetically modified organisms (plants, animalsand microorganisms).

19, 20 248 - 254

30 The risks and benefits associated with the use of geneticallymodified organisms; the methods used to compare thecontributions of nature and nurture to brain development,including evidence from the abilities of newborn babies, animalexperiments, studies of individuals with damaged brain areas,twin studies and cross-cultural studies.

13, 21 255 257and

228 - 237

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teaching scheme - a2 context approach

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