teaching scheme - a2 concept

7/30/2019 Teaching Scheme - A2 Concept

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GCE A2 Biology Teaching Scheme (ConceptApproach)


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A2 Teaching scheme

This teaching scheme is based on the concept approach.

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

Both teaching schemes, concept and context, 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

Weeknumber

Content of lessons Specificationreferences

Pagenumbers (*)

Unit 4 Topic 5: On the wild side

31 The effect of biotic and abiotic factors on the numbersand distribution of organisms in a habitat; how theconcept of niche accounts for the distribution andabundance of organisms in a habitat; the concept ofsuccession leading to a climax community.

10, 12, 13 18 - 33

32 How to carry out a study on the ecology of a habitatto produce valid and reliable data (including the useof quadrats and transects to assess abundance and

distribution of organisms and the measurement ofabiotic factors, e.g. solar energy input, climate,topography, oxygen availability and edaphic factors).

11

33 The causes of global warming including the role ofgreenhouse gases (carbon dioxide and methane, CH4)in the greenhouse effect; analysis and interpretationof different types of evidence for global warming andits causes (including records of carbon dioxide levels,temperature records, pollen in peat bogs anddendrochronology), recognising correlations and causalrelationships; how data can be extrapolated to makepredictions, 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 aboutcontroversial issues, such as what actions should betaken to reduce global warming, or the degree towhich humans are affecting global warming, cansometimes depends on who is reaching theconclusions; the effects of global warming (risingtemperature, changing rainfall patterns and changesin seasonal cycles) on plants and animals (distributionof species, 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 structure of chloroplasts in relation to their role inphotosynthesis; the overall reaction of photosynthesis asrequiring energy from light to split apart the strong bonds inwater molecules, storing the hydrogen in a fuel (glucose) bycombining it with carbon dioxide and releasing oxygen into theatmosphere; the light-dependent reactions of photosynthesis,including how light energy is trapped by exciting electrons inchlorophyll and the role of these electrons in generating ATP,reducing NADP and producing oxygen through the photolysis ofwater.

2, 3, 4 10 - 16

2 How phosphorylation of ADP requires energy and how hydrolysisof ATP provides an immediate supply of energy for biologicalprocesses; the light-independent reactions of photosynthesis asthe reduction of carbon dioxide using the products of the light-dependent reactions (carbon dioxide fixation in the Calvin cycle,the role of GP, GALP, RuBP and RUBISCO); the products aresimple sugars which are used by plants, animals and otherorganisms in respiration and the synthesis of new biologicalmolecules (including polysaccharides, amino acids, lipids andnucleic acids).

5, 6 10 11and

16 - 17

3 Calculations of net primary productivity and the relationshipbetween gross primary productivity, net primary productivity and

plant respiration; calculations to determine the efficiency ofenergy transfers between trophic levels.

7, 8 34 - 37

4 How an understanding of the carbon cycle can lead to methodsthat can help to reduce atmospheric levels of carbon dioxide(including the use of biofuels and reforestation); the effect ofincreasing temperature on the rate of enzyme activity in plants,animals and microorganisms.How to investigate the effects of temperature on thedevelopment of organisms (e.g. seedling growth rate, brineshrimp hatch rates).

9, 16, 17 38 - 53

5 How evolution (a change in the allele frequency) can come about

through gene mutation and natural selection; how reproductiveisolation can lead to speciation.

21, 22 54 - 57

6 The role of the scientific community in validating new evidence(including molecular biology, e.g. DNA, proteomics) supportingthe accepted scientific theory of evolution (scientific journals,the peer review process, scientific conferences).

23 58 - 61

Unit 4 Topic 6: Infection, immunity and forensics

7 The nature of the genetic code (triplet code, non-overlappingand degenerate); 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

2, 3, 4 72 - 77

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(antisense) DNA strand in transcription, codons on messengerRNA; how one gene can give rise to more than one proteinthrough post-transcriptional changes to messenger RNA.

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 Differences between the structure of bacteria and viruses; therole of microorganisms in the decomposition of organic matterand the recycling of carbon.

8, 9 82 87and91

10 The major routes pathogens may take when entering the bodyand the role of barriers in protecting the body from infection,including the roles of skin, stomach acid, gut and skin flora; howbacterial and viral infectious diseases have a sequence ofsymptoms that may result in death, including the diseases causedby Mycobacterium tuberculosis (TB) and HumanImmunodeficiency Virus (HIV).

10 ,11 92 95and

116 - 123

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

12, 13, 14 96 - 103

12 How individuals may develop immunity (natural, artificial, active,passive); discuss how the theory of an evolutionary racebetween pathogens and their hosts is supported by the evasionmechanisms as shown by Human Immunodeficiency Virus (HIV)and Mycobacterium tuberculosis (TB); differences between

bacteriostatic and bactericidal antibiotics.

15, 16, 17 112 115,

118, 123and

104 - 107

13 How an understanding of the contributory causes of hospitalacquired infections have led to codes of practice relating toantibiotic prescription and hospital practice relating to infectionprevention and control; how to determine the time of death of amammal by examining the extent of decomposition, stage ofsuccession, forensic entomology body temperature and degree ofmuscle contraction.How to investigate the effect of different antibiotics onbacteria.

18, 19, 20 108 111,

66 71and107

Unit 5 Topic 7: Run for your life

14 The structure of a muscle fibre and the structural andphysiological differences between fast and slow twitch musclefibres; the contraction of skeletal muscle in terms of the slidingfilament theory, including the role of actin, myosin, troponin,tropomyosin, calcium ions (Ca2+), ATP and ATPase; the way inwhich muscles, tendons, the skeleton and ligaments interact toenable movement, including antagonistic muscle pairs, extensorsand flexors.

2, 3, 4 142 - 151

15 The overall reaction of aerobic respiration as splitting of therespiratory substrate (e.g. glucose) to release carbon dioxide and

reuniting of hydrogen with atmospheric oxygen with the release

5, 6, 7, 8 128 - 135

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of a large amount of energy; how phosphorylation of ADP requiresenergy and how hydrolysis of ATP provides an accessible supply ofenergy for biological processes; the roles of glycolysis in aerobicand anaerobic respiration, including the phosphorylation ofhexoses, the production of ATP, reduced coenzyme and pyruvicacid (details of intermediate stages and compounds are notrequired).

How to investigate rate of respiration practically.16 The role of the Krebs cycle in the complete oxidation of glucose

and formation of carbon dioxide (CO2), ATP, reduced NAD andreduced FAD (names of other compounds are not required) andrespiration is a many-stepped process with each step controlledand catalysed by a specific intracellular enzyme; the synthesis ofATP by oxidative phosphorylation associated with the electrontransport chain in mitochondria, including the role ofchemiosmosis and ATPase; the fate of lactate after a period ofanaerobic respiration in animals.

9, 10 ,11 136 141and

133 - 134

17 Cardiac muscle is myogenic and the normal electrical activity of

the heart, including the roles of the sinoatrial node (SAN), theatrioventricular node (AVN) and the bundle of His, and how theuse of electrocardiograms (ECGs) can aid the diagnosis ofcardiovascular disease (CVD) and other heart conditions; howvariations in ventilation and cardiac output enable rapid deliveryof oxygen to tissues and the removal of carbon dioxide fromthem, including how the heart rate and ventilation rate arecontrolled and the roles of the cardiovascular control centre andthe ventilation centre.

12, 13 152 157

and159

18 How to investigate the effects of exercise on tidal volume andbreathing rate using data from spirometer traces. The principleof negative feedback in maintaining systems within narrow limits.

14, 15 158 - 161

19 The concept of homeostasis and its importance in maintaining thebody in a state of dynamic equilibrium during exercise, includingthe role of the hypothalamus and the mechanisms ofthermoregulation; how genes can be switched on and off by DNAtranscription factors including hormones.

16, 17 162 167and

180 - 181

20 Analysis and interpretation of data on possible disadvantages ofexercising too much (wear and tear on joints, suppression of theimmune system) and exercising too little (increased risk ofobesity, coronary heart disease (CHD) and diabetes), recognisingcorrelation and causal relationships.

18 168 - 173

21 How medical technology, including the use of keyhole surgery

and prostheses, is enabling those with injuries and disabilities toparticipate in sports, e.g. cruciate ligament repair using keyholesurgery and knee joint replacement using prosthetics; two ethicalpositions relating to whether the use of performance-enhancingsubstances by athletes is acceptable.

19, 20 174 179

and182 - 183

Unit 5 Topic 8: Grey matter

22 How plants detect light using photoreceptors and how theyrespond to environmental cues; the structure and function ofsensory, relay and motor neurones including the role of Schwanncells and myelination.

2, 3 188 193and

198 - 199

23 The mechanism of conduction of a nerve impulse (action 4, 5 200 - 209

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potential) along an axon, including changes in membranepermeability to sodium and potassium ions and the role of thenodes of Ranvier; the structure and function of synapses,including the role of neurotransmitters, such as acetylcholine.

24 How the nervous systems of organisms can detect stimuli withreference to rods in the retina of mammals, the roles ofrhodopsin, opsin, retinal, sodium ions, cation channels andhyperpolarisation of rod cells in forming action potentials in theoptic neurones; how the nervous systems of organisms can causeeffectors to respond as exemplified by pupil dilation andcontraction; comparisons between the mechanisms ofcoordination in plants and animals, i.e. nervous and hormonal,including the role of IAA in phototropism (details of individualmammalian hormones are not required).

6, 7, 8 212 219and

194 - 197

25 The location and functions of the regions of the human brainscerebral hemispheres (ability to see, think, learn and feelemotions), hypothalamus (thermoregulate), cerebellum(coordinate movement) and medulla oblongata (control the

heartbeat); the use of magnetic resonance imaging (MRI),functional magnetic resonance imaging (fMRI) and computedtomography (CT) scans in medical diagnosis and investigatingbrain structure and function.

9, 10 220 - 227

26 Discussion of whether there exists a critical window withinwhich humans must be exposed to particular stimuli if they are todevelop their visual capacities to the full; the role animal modelshave played in developing explanations of human braindevelopment and function including Hubel and Wieselsexperiments with monkeys and kittens.

11, 12 228 - 231

27 The methods used to compare the contributions of nature andnurture to brain development, including evidence from the

abilities of newborn babies, animal experiments, studies ofindividuals with damaged brain areas, twin studies and cross-cultural studies; how animals, including humans, can learn byhabituation.

How to investigate habituation to a stimulus.

13, 14, 15 232 - 241

28 Discussion of the moral and ethical issues relating to the use ofanimals in medical research from two ethical standpoints; howimbalances in certain naturally occurring brain chemicals cancontribute to ill health (e.g. dopamine in Parkinsons disease andserotonin in depression) and to the development of new drugs.

16, 17 222and

242 - 245

29 The effects of drugs on synaptic transmissions, including the useof L-Dopa in the treatment of Parkinsons disease and the actionof MDMA in ecstasy; discussion about how the outcomes of theHuman Genome Project are being used in the development ofnew drugs and the social, moral and ethical issues this raises.

18, 19 242 - 251

30 How drugs can be produced using genetically modified organisms(plants and animals and microorganisms); discussion of the risksand benefits associated with the use of genetically modifiedorganisms.

20, 21 252 - 257

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teaching scheme - a2 concept

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