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Questions Q1. * Explain how blood glucose levels are controlled in people who do not have diabetes. 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Q2. * Explain how the human body responds to an external temperature of 40 °C. 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Q3. * Carbon is present in a wide variety of compounds in the carbon cycle. Describe how carbon is cycled in the environment. 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Q4. * Body movement is controlled by nerve impulses. Explain how impulses are transmitted in a reflex arc to prevent a person from injuring themselves. 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Q5. Eye colour inheritance The diagram below shows the inheritance of eye colour in a family. The allele for brown eyes is (B) and the allele for blue eyes is (b). * Explain why two parents with the alleles BB and bb for eye colour are unlikely to produce offspring with blue eyes. You should draw a genetic diagram or Punnett square to help with your explanation. 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Q6. Auxins are plant hormones. * Fruit ripening is one use of plant hormones. Describe the other uses of plant hormones in crop production. 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Q7. * Describe how different pathogens are spread within human populations. 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Q8. * In the UK, the external temperature can drop below 0 °C. Explain how the human body maintains a stable internal temperature when the external temperature is 0 °C. 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Q9. * MRSA is a bacterial infection. The graph shows the number of cases of hospital patients with MRSA infections from 1993 to 2005. Explain the trend in the graph, even though the patients were treated with antibiotics. 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Q10. * Explain how an increase in the production of pollutants can be due to an increase in human population. Include both air and water pollution in your answer. 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Q11. Cystic fibrosis (CF) is a recessive genetic disorder. The recessive allele is shown as f and the dominant allele as F. * Sickle cell disease is another genetic disorder caused by a recessive allele (d). Explain the inheritance of sickle cell disease in a family with a heterozygous father and a homozygous recessive mother. You should use a genetic diagram or Punnett square and percentage outcomes in addition to your explanation. 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Q12. The family pedigree shows the inheritance of sickle cell disease through three generations. * Explain why it is important that individuals X, Y and Z have pedigree analysis completed before they consider having children. You should use diagrams and mathematical calculations to illustrate your answer. 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Examiner's Report Q1. This question was well answered by the majority of candidates although there was some understandable confusion with glucose, glucagon, glycogen. These mistakes did not negate the candidates reaching a particular level, but did act to show that there was a lack of clarity in their answer and thus put them to the bottom of the level. Results Plus: Examiner Comments In this response the candidate is clearly confused about the role of the organs and the role of the hormones involved. They do however have an idea about how glucose levels are controlled and therefore were put into level 1. The response was awarded one mark because of the many misconceptions in the answer. Results Plus: Examiner Comments This is a good answer which shows the two control mechanisms. However it does not give the detail of the role of the liver and glycogen in the process so is a level 2 answer. Overall the answer is clear and there is good use of scientific terminology so the candidate gains four marks. Results Plus: Examiner Comments This is an example of a clear and correct response to the question, both methods of control are mentioned and the roles of the organs and the hormones are accurate. Q2. This was well accessed by all candidates although a few missed that this was a warm temperature and gave details of how the body responds to a cold temperature. The main responses expected included the role of the sweat glands releasing water and salts onto the skin surface which cools it down when it is evaporated off. The concept and explanation of vasodilation and the role of the erector muscle on the hairs causing them to lay flat thus reducing the insulation effect. Some references to the role of sebum in causing the sweat to spread were also seen. Results Plus: Examiner Comments Despite the crossing out and slightly 'stop start' sentencing this response covers all the main areas required by the generic marking grid in sufficient detail. Level 3 given and no major issues with QWC so 6 marks are awarded. Results Plus: Examiner Comments This is a classic example of how a candidate can lose marks due to an incorrect reading of the question. They clearly have some knowledge of thermoregulation as illustrated by their comments on homeostasis but they have followed the wrong track and the remainder of the response is either incorrect or not relevant so 0 marks can be awarded. Results Plus: Examiner Tip Make sure you focus on the question being asked and not just write down all you know about a topic. Q3. These questions were accessed well with most candidates who responded using a variety of methods such as diagrams, flow charts and even bullet points, all of which are acceptable. The six mark questions have caused some worries for teachers and candidates however these were tackled reasonably well by candidates. The majority of candidates getting into band 2 or 3 giving one to four marks. The better candidates were able to access the highest band and attain six marks. Results Plus: Examiner Comments This response has managed to cover most of the aspects of the carbon cycle and so accesses band 3 but the flow is not coherent and it lacks some clarity so ends up at five marks. Results Plus: Examiner Tip For the six mark questions it is possible to draw this as a diagram, as long as it is annotated, or a flow chart. In some cases bullet pointed lists can still gain maximum marks. As you can see this is a more limited response but nevertheless the candidate has managed to acces mark band 2. Results Plus: Examiner Comments The candidate has manged to get to band 2 as there is a method of removal of carbon dioxide by plants and a method of returning carbon dioxide to the atmosphere. The response does lack a little clarity so overall this gains a mark of three. Results Plus: Examiner Tip Always choose the best method of presenting the information, for the carbon cycle an annotated diagram may be the best method. Q4. Most candidates were able to access this question at some level, with a majority being able to name the neurones involved, but sometimes candidates muddled the order. The role of the synapse was well understood and several candidates were able to explain the role of the myelin sheath in insulating the impulse. Many candidates were also able to explain how impulses travel along neurones and the role of neurotransmitters across the synapse. Results Plus: Examiner Comments This is a good, clear response. The candidate included clear detail about the path of the reflex arc and also the role of the synapse. The method of travel along neurones as electrical signals was also given, putting the candidate into band 3. Spelling, grammar and the clarity of writing are good so 6 marks were awarded. Results Plus: Examiner Comments This candidate has put in some detail about the reflex arc but some of this is muddled and out of order so this response goes into mark band 1. The answer is well written and spelling and grammar are correct so 2 marks are awarded. Q5. No Examiner's Report available for this question Q6. In general candidates managed this question well with a fair number falling into the mid-band with 2 marks. Some candidates were unable to give any other uses for plant hormones and therefore could not be awarded all of the marks available. In the 6- mark questions the answers are marked against a generic marking grid, which puts the candidates work into a level. Level 1 included one use of plant hormones to commercial growers. Level 2 was two or more uses of plant hormones and Level 3 was two or more uses in detail with a correct link between at least 1 hormone and its role in crop production. Results Plus: Examiner Comments This candidate has successfully given several other uses of plant hormones and given some detail of how the hormones work. This is enough to put them into Level 2 of the mark scheme. Spelling, grammar and quality of writing are acceptable for a Level 2 answer so the candidate is awarded 4 marks. To move up to the next level the candidate should have given a little more detail, including the names of at least one hormone linked to its use. Results Plus: Examiner Tip With the 6-mark questions ensure that you take time with spelling, grammar and quality of writing in order to gain the maximum marks. Results Plus: Examiner Comments This candidate has managed to give one use of plant hormones as selective weed-killers, which puts them into Level 1 on the mark scheme. At this level the spelling and grammar do not have to be as high quality as at the higher levels and this response was considered sufficient to award the QWC mark. This answer was awarded 2 marks. Results Plus: Examiner Tip Try to make sure you answer the question being asked and do not inadvertently move onto other subjects which are irrelevant to the question and therefore cannot be credited. Results Plus: Examiner Comments This candidate has written well, using good spelling, grammar and sentence construction. They have detailed the uses of plant hormones and linked the use of auxins and gibberellins to their role in the plant. This candidate has been awarded Level 3 for 6 marks. Results Plus: Examiner Tip Always try to tailor your response to the space available on the exam paper as it should guide you about how much should be written. Q7. No Examiner's Report available for this question Q8. It was very pleasing to note how well the candidates did in this session on both of the 6 mark questions, with the majority of candidates gaining 4 of the 6 marks available, which is appropriate for the cohort. Candidates are much better able to write in continuous prose and put coherent thoughts down in a logical order. Please note that all the indicative content is not needed for the candidate to gain full marks, as these questions are not marked on a point by point basis, but from the generic marking grid with the level of detail and the coherent and logical communication being paramount. This was a very typical response to the question with a simple explanation of two methods of raising body temperature. The answer flows well, and there is very good evidence that the candidate clearly understands the mechanisms of thermoregulation. Results Plus: Examiner Comments This candidate has gained 4 marks here and has produced a well rounded answer. To increase the marks, another method of thermoregulation should be mentioned with a little more detail on at least one of the methods. Results Plus: Examiner Comments This is a clear example of an answer in level 2. Some good detail of the methods of thrermoregulation is included and the answer flows coherently. Grammar and spelling is used to good effect so 4 marks here. Marks are not deducted for minor spelling errors but rather for the overall quality of the work. Q9. In this case the candidate has given a good description of the graph which puts the candidate into level 1. As the answer flows well, and is logically ordered, with most spellings and grammar correct, this is worth 2 marks. Results Plus: Examiner Comments There were 2 parts to this question, the first part about the graph and the trends and the second part about why the trend is as it is. This candidate has not managed to access the second section. This candidate has given a good decription of the graph and also has attempted to give reasons for the increasing trend in MRSA, this has put them into level 2. As the answer uses good english and grammar and flows coherently this is awarded 4 marks. Results Plus: Examiner Comments To gain 6 marks here the candidate would need to give details as to how antibiotic resistant bacteria came to evolve. Q10. This question was well accessed by all candidates. The problems encountered were that some candidates only referred to either air or water pollution and not both types. There were some very creditable responses involving eutrophication and nitrates and phosphate pollution as well as the role of sulphur dioxide in acid rain as well as carbon dioxide and its link to global warming or the greenhouse effect. Almost all candidates were able to score on this question. Results Plus: Examiner Comments 4 marks are awarded for this response, both types of pollution are explained but only in limited detail and there was no mention of the compounds involved in this pollution. Results Plus: Examiner Tip Try to be as detailed as possible in these answers without rambling. Results Plus: Examiner Comments The candidate has only really made one comment about fossil fuels which is creditable so this candidate can access level 1 and was awarded 2 marks. The remainder of the response is a repeat of the stem or the same point. Q11. Overall this question was answered well, with most candidates able to draw a correct Punnett square or genetic diagram. Frequently the description of the inheritance was less well answered and this put candidates into band 2 with a maximum of 4 marks. The question also asked for percentage outcomes, which were generally calculated correctly and explained. Common mistakes were references to genes instead of alleles, a mix-up with homozygous and heterozygous and, in some cases, candidates using letters for alleles that could not be interpreted as lower- or upper-case letters. Results Plus: Examiner Comments This candidate answered the question fully and effectively. The Punnett square is clear and the letters easy to distinguish. Percentage outcomes are correctly allocated and the Punnett square explained in detail. The candidate gained all 6 marks here. Results Plus: Examiner Tip Candidates should ensure that they address all parts of the 6-mark question in order to access all the marks. Results Plus: Examiner Comments As the candidate did not answer the question, which was to explain the inheritance, they could only access mark band 1. 2 marks were awarded here for the correct Punnett square. The percentage outcome was also not explained so no credit could be given as we did not know what it referred to. Q12. Most candidates managed to attain Level 1 or 2 in this question although there were many very good responses involving a Punnett square of potential offspring and/or inheritance patterns. To attain Level 1 the candidates either had to correctly describe the genotypes or penotypes of X,Y and Z or give an outline of why they should have pedigree analysis. For Level 2, both of these were required and for Level 3 some mention of inheritance patterns or potential outcomes calculated and explained were also required. Results Plus: Examiner Comments This response is worthy of Level 2. The candidate has correctly identified the genotype and phenotype of X, Y and Z and has also explained the need for pedigree analysis. There is not enough evidence of thought on possible inheritance patterns of offspring to justify Level 3. QWC mark is given so 4 marks in total. Results Plus: Examiner Tip On the 6-mark questions try to organise your thoughts before starting to write. This will help with the clarity of your writing and ensure you gain the QWC marks available. Results Plus: Examiner Comments The candidate displays a knowledge of inheritance and the need for pedigree analysis. However, there is a mistake in the identification of the genotype of person X so this candidate is put into Level 1 with 2 marks awarded. Mark Scheme Q1. QWC Question Number * Indicative Content An explanation linking some of the following points When blood glucose is Mark (6) Level 1 0 1-2 2 3-4 3 5-6 high• insulin is released from the pancreas • the insulin converts the excess glucose • into glycogen • which is stored in the liver • blood glucose levels are reduced When blood glucose levels are low• glucagon is released from the pancreas • the glucagon coverts glycogen • from the liver • into glucose • into glucose This is a homeostatic mechanism which maintains the correct glucose levels in the bloodstream No rewardable content • a limited explanation of blood glucose regulation including the role of hormones, specific hormones do not need to be mentioned • the answer communicates ideas using simple language and uses limited scientific terminology • spelling, punctuation and grammar are used with limited accuracy • a simple explanation of blood glucose regulation including the role of insulin or glucagon and some of the body organs involved • the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately • spelling, punctuation and grammar are used with some accuracy • a detailed explanation of blood glucose regulation including the role of the liver and pancreas and the methods of reducing and raising blood glucose concentrations • the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately • spelling, punctuation and grammar are used with few errors Q2. Indicative Content * Mark A explanation to include some of the following homeostasis / regulation of the body's internal environment controlled by the hypothalamus / thermoregulatory hypothalamus / thermoregulatory centre monitors blood temperature negative feedback mechanism sweat rate increases sweat glands will release sweat on to skin surface evaporation of this sweat / water will remove heat energy from skin hairs on skin's surface lay flat no trapping of insulating air layer so body loses heat Level 1 0 1-2 vasodilation occurs widening of the arterioles / blood vessels eq, near the skin delivers warm blood to skin surface body loses heat (6) by radiation No rewardable content a limited explanation of at least one method of thermoregulation the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple explanation including at least two methods of thermoregulation the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed explanation of at least 3 methods of thermo regulation. Use of the term vasodilation or including information on the process of homeostasis the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q3. Question Number QWC Indicative Content * Level 1 0 1-2 2 3-4 3 5-6 Mark A description including some of the following points: • photosynthetic material/plants will remove CO2 from the atmosphere • these plants will use the CO2 to make glucose • plant respiration will release CO2 into the atmosphere • animals will eat the plants which contain carbon • animals and plants will eventually die and decay due to microbial/bacterial action releasing CO2 • the combustion/burning of fossil fuels will release CO2 into the atmosphere • the burning of carbon based products made from trees will release CO2 into the (6) atmosphere No rewardable content • a limited description of one of the processes of the carbon cycle • the answer communicates ideas using simple language and uses limited scientific terminology • spelling, punctuation and grammar are used with limited accuracy • a simple description of two of the processes of the carbon cycle including one method of adding carbon dioxide and one method of removing carbon dioxide • the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately • spelling, punctuation and grammar are used with some accuracy • a detailed description of most of the processes of the carbon cycle that releases and removes carbon dioxide • the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately to describe the carbon cycle • spelling, punctuation and grammar are used with few errors Q4. Indicative Content * Level 1 0 1-2 An explanation including the following points in a logical order: a reflex response is an involuntary response reflex responses do not involve the brain reflex responses involve sensory neurones reflex responses involve relay neurones reflex responses involve motor neurones relay neurones are in the spinal cord impulses travel along neurones as electrical signals the axon is insulated by the myelin sheath which ensures the electrical signal does not lose energy at the junction between two neurones there is a synapse the message is carried across the synapse by neurotransmitters the message travels from the stimulus along the axon and dendron of the sensory neurone to the spinal cord the reflex arc is important to keep the body safe No rewardable content Mark (6) A limited written explanation of some of the neurones involved in the reflex arc or a limited explanation of how messages /impulses are transmitted as electrical signals the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 A simple explanation of the neurones involved in the reflex arc in the correct order, with the method of transmission along neurones, one neurone may be missing or a detailed description of all of the neurones in the reflex arc and the role of the CNS the answer communicates ideas showing some evidence of clarity and organisation and mostly uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 A detailed explanation of the neurones involved in the reflex arc in the correct order, with the method of transmission along neurones including the role of the synapse and/or myelin sheath. the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q5. Question Number QWC Indicative Content * Level 1 0 1-2 2 3-4 Mark A Punnett square or genetic diagram showing the following gametes and offspring If a Punnett square or genetic diagram is not drawn, then a full description of this genetic inheritance is required • both parents will give one allele to the possible offspring • one parent can only give a dominant/B allele • one parent can only give a recessive/b allele • a dominant and recessive allele will result in heterozygous offspring • offspring heterozygous for eye colour will have brown eyes • because the allele for brown eyes is dominant over the allele for blue eyes • to be blue eyed, the offspring must inherit one recessive allele(b) from each (6) parent No rewardable content • a limited explanation is provided by the candidate of the inheritance with a genetic diagram / Punnett square with either correct gametes or offspring only • the answer communicates ideas using simple language and uses limited scientific terminology • spelling, punctuation and grammar are used with limited accuracy • the genetic diagram / Punnett square is correct for both gametes and offspring • there is a basic outline of the inheritance but the details of the inheritance are lacking, • the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately 3 5-6 • spelling, punctuation and grammar are used with some accuracy • the Punnett square / genetic diagram is complete and accurate for both gametes and offspring • the steps of inheritance of eye colour are outlined clearly • the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately • spelling, punctuation and grammar are used with few errors Q6. Indicative Content QWC Level 1 * 0 1-2 Mark A description to include some of the following points selective weedkillers allows broad-leaved plants to grow uncontrollably and die narrower-leaved plants and crops left unaffected auxins and or gibberellins are used rooting powders plant cuttings are dipped into rooting powder roots develop rapidly large number of plants can be produced from the same plant no need to wait for plants to grow from seeds auxins are used seedless fruit production the fruit will develop but the seeds inside will not fruits are able to grow larger (larger biomass) gibberellins are (6) used No rewardable content a limited description of at least one use of plant hormones the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description of two or more uses of plant hormones the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed description of two or more uses of plant hormones with at least auxin, gibberellins or other relevant hormone in the correct context the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q7. Question Number QWC Indicative Content * Level 1 0 1-2 2 3-4 3 5-6 Mark A description of how pathogens are spread and how they enter the human body in a logical order • cholera bacteria ingested through the drinking of ‘dirty’ water • Salmonella bacteria ingested through contaminated food products / spread by direct contact • influenza virus spread through droplet inhalation/airborne process • athlete’s foot fungus spread by contact with fungal spores • HIV spread by exchange of contaminated body fluids • dysentery infection / bacteria spread through housefly vector • malaria protozoa spread by the Anopheles mosquito (6) No rewardable content • few examples of pathogens are given and/or wrongly linked to their sources of infection or method of transmission • the answer communicates ideas using simple language and uses limited scientific terminology • spelling, punctuation and grammar are used with limited accuracy • there are several examples of pathogens mentioned linked to their source of infection • there is a link to the method of transmission for each of the pathogen • the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately • spelling, punctuation and grammar are used with some accuracy • the majority of the pathogens are mentioned and linked to their source of infection • the method of transmission is described accurately for each of the pathogens • the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately • spelling, punctuation and grammar are used with few errors Q8. QWC * Indicative Content An explanation of thermoregulation in response to a low external temperature hypothalamus detects a drop in the blood's temperature vasoconstriction blood vessels near the surface of the skin constrict reduce blood flow to the skin reduce heat loss via radiation Mark hair erector muscles contract raises hairs on body to trap a layer of insulating air between cold environment and body surface reduce heat loss via conduction shivering will occur skeletal muscles contract and relax involuntarily produces respiratory heat to warm up body Level 1 0 1-2 hypothalamus detects a rise in the blood's temperature reference to (6) negative feedback No rewardable content a limited explanation is provided for one of the methods of raising body temperature the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple explanation of two of the methods of raising body temperature or one method explained in detail, alternatively a limited explanation of all three methods the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed explanation of at least one of the methods of raising body temperature with a simple explanation of two others most of the steps are identified and are in a logical order and reference may be made to hypothalamus and negative feedback the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q9. QWC Level 1 * 0 1-2 Indicative Content Mark An explanation of how MRSA has increased since 1993 also using the evaluation of data from the graph the number of patients suffering from MRSA has increased / more cases of MRSA by over 366 000 since 1993 data quoted from the graph ref to poor hygiene in hospitals MRSA is a bacterium that is resistant to antibiotics individual bacteria show variation when a bacterial infection is treated with antibiotics those bacteria with low resistance are destroyed first the more resistant bacteria survive if a patient stops taking the antibiotics then the resistant bacteria will live to reproduce the new bacteria will also be resistant to antibiotics these bacteria will not be able to be treated with antibiotics so the number of cases (6) continue to rise No rewardable content a limited description of the graph only or the increase in bacteria only the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple description of the graph with a limited explanation of how bacteria continued to increase the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed explanation (with data) using the graph of the emergence of resistant bacteria which then reproduce, linked to antibiotic treatment most of the steps are identified and are in a logical order the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q10. Indicative Content QWC * Leve l 1 0 1-2 Mark A explanation to include some of the following Air pollution Humans burn more fossil fuels coal/oil/gas nitrogen oxides in car exhausts Releasing sulfur dioxide Which causes acid rain carbon dioxide gas causes climate change deforestation causing increase in carbon dioxide increased population – increased respiration more carbon dioxide Water pollution Humans produce sewage Sewage contains phosphates Phosphates are water pollutants Nitrate pollution can be caused by the overuse of fertilisers Nitrate pollution causes (6) eutrophication No rewardable content a limited explanation of how humans effect pollution – increasing pollution in either air or water the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 a simple explanation of both air and water pollution including the effects of one air and one water pollutant or a detailed explanation of either air or water pollution the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed explanation of the effect of humans on both air and water pollution including the role of sulphur dioxide or carbon dioxide and nitrates or phosphates the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q11. * Level 1 0 1-2 Indicative Content Mark An explanation including the following points: A Punnett square or genetic diagram showing the following gametes and offspring (6) mother gametes = d, d father gametes = D, d offspring = 50% Dd, 50% dd probability of offspring with sickle cell disease = 50% probability of carrier / heterozygous = 50% both parents will give one allele to the possible offspring the father can give either the dominant or recessive allele the mother can only give a recessive allele a dominant and recessive allele will result in heterozygous offspring No rewardable content Limited written explanation is provided by the candidate of the inheritance and / or a genetic diagram/ Punnett square with only correct gametes or offspring the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 The genetic diagram/ Punnett square is correct for both gametes and offspring with a simple explanation the answer communicates ideas showing some evidence of clarity and organisation and mostly uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 The Punnett Square/genetic diagram is complete and accurate for both gametes and offspring plus percentage outcomes and a detailed explanation of inheritance of CF the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors Q12. QWC * Indicative Content Mark A explanation to include some of the following points: Pedigree analysis would show the likelihood of their offspring inheriting the disorder Pedigree analysis should also be carried out on the partners of the third generation. X is not a carrier X is homozygous dominant and does not have sickle cell disease The parents of X are heterozygous / his sister has sickle cell so will not pass on the allele for the disease to offspring if his partner is a carrier there will be a 50% chance of the child being a carrier Y and Z are carriers of the sickle cell allele Y and Z are heterozygous The mother of Y has sickle cell / Y will inherit the sickle cell allele The parents of Z do not have sickle cell / mother is a carrier/heterozygous They have a 50% chance of passing the sickle cell allele onto their potential offspring If their partners were also carriers There would be a 25% chance that the offspring will have (6) the sickle cell disease There would be a 50% chance that the offspring would also carry the allele for sickle cell diseaseExample Punnett square: Level 1 0 1-2 No rewardable content a limited explanation the genetic profile of X,Y and Z or an explanation of the use of pedigree analysis the answer communicates ideas using simple language and uses limited scientific terminology spelling, punctuation and grammar are used with limited accuracy 2 3-4 A simple explanation of the genetic profile of X, Y and Z and an explanation of the use of pedigree analysis the answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately spelling, punctuation and grammar are used with some accuracy 3 5-6 a detailed explanation of the genetic profile of X, Y and Z and explanation of the use of pedigree analysis plus either an explanation of one genotype or a prediction of one of the offspring outcomes the answer communicates ideas clearly and coherently uses a range of scientific terminology accurately spelling, punctuation and grammar are used with few errors
