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1 Centre Number Surname Candidate Number Other Names For Examiner s Use Total EMPA mark Notice to Candidate. The work you submit for assessment must be your own. If you copy from someone else or allow another candidate to copy from you, or if you cheat in any other way, you may be disqualified. Examiner s Initials Candidate Declaration. I have read and understood the Notice to Candidate and can confirm that I have produced the attached work without assistance other than that which is acceptable under the scheme of assessment. Candidate Signature Date Section Task 1 Mark General Certificate of Education Advanced Level Examination June 2014 Task 2 Section A Section B Human Biology HBI6X TOTAL EMPA MARK Unit 6X A2 Externally Marked Practical Assignment Written Test For submission by 15 May 2014 For this paper you must have: l your Task Sheet 2, your results and your calculations l a ruler with millimetre measurements l a calculator. Instructions l Use black ink or black ball-point pen. l Fill in the es at the top of this page. l Answer all questions. l You must answer the questions in the spaces provided. Do not write around each page or on blank pages. l Do all rough work in this book. Cross through any work you do not want to be marked. Time allowed l 1 hour 15 minutes Information l The marks for questions are shown in brackets. l The maximum mark for this paper is 30. l You will be marked on your ability to: use good English organise information clearly use scientific terminology accurately. Details of additional assistance (if any). Did the candidate receive any help or information in the production of this work? If you answer yes give the details below or on a separate page. Yes No Teacher Declaration: I confirm that the candidate has met the requirements of the practical skills verification (PSV) in accordance with the instructions and criteria in section 3.8 of the specification. Practical Skills Verification Yes Signature of teacher... Date... As part of AQA s commitment to assist students, AQA may make your coursework available on a strictly anonymous basis to teachers, examining staff and students in paper form or electronically, through the Internet or other means, for the purpose of indicating a typical mark or for other educational purposes. In the unlikely event that your coursework is made available for the purposes stated above, you may object to this at any time and we will remove the work on reasonable notice. If you have any concerns please contact AQA. To see how AQA complies with the Data Protection Act 1988 please see our Privacy Statement at aqa.org.uk /E7w HBI6X

2 2 Section A These questions relate to your investigation into inheritance of Angelman syndrome. Use your Task Sheet 2, your results and your statistical calculation to answer the questions. Answer all the questions in the spaces provided. Your investigation used two coins as a model for the inheritance of Angelman syndrome. 7 Give two ways in which it is a good model to use (a) There are a number of different genetic causes of Angelman syndrome. In your investigation of inheritance it was said to be due to a faulty allele of a gene on chromosome 15 from the mother. Sometimes Angelman syndrome is due to that gene being missing. Would your model change if you were investigating inheritance of Angelman syndrome due to a missing gene? Explain your answer. [1 mark]

3 3 8 (b) Sometimes Angelman syndrome is due to epigenetic factors that affect the gene on chromosome 15 from the mother. Explain how epigenetic factors could produce Angelman syndrome. [3 marks] 9 A student read an article. The article gave some of the symptoms of Angelman syndrome. People with Angelman syndrome have learning difficulties and difficulty with coordination. The article also claimed that they laugh more than people who do not have Angelman syndrome. He thought that it would be difficult to test this claim. Suggest three reasons why. [3 marks] Turn over for the next question Turn over

4 4 10 Figure 1 shows a family tree for a family where Angelman syndrome was caused by a mutation of the gene on chromosome 15. Figure Key Female Male Healthy male with one mutated allele of the gene Healthy female with one mutated allele of the gene 6 Angelman syndrome female 10 (a) Person 3 has the mutated allele of the gene but her brother (person 5) does not. Use Figure 1 to explain how. [1 mark] 10 (b) Person 3 and person 6 both have one copy of the mutated allele but only person 6 has Angelman syndrome. Explain why. [1 mark]

5 5 10 (c) Genetic screening for Angelman syndrome is available. Person 3 had good medical care during pregnancy but was not offered genetic screening for Angelman syndrome. Suggest why. 13 Turn over for the Resource Sheet Turn over

6 6 Resource Sheet Introduction Some women choose IVF because they are infertile. One recent study suggested that the risk of genetic disorders such as Angelman syndrome might be higher in children conceived by one rarely used form of IVF. Resource A Scientists investigated causes of infertility in women. They carried out a survey of 574 women who were about to start IVF treatment. The women were aged between 20 and 45 years and none had been pregnant before. The scientists recorded the cause, or causes, of each woman s infertility. Their results are shown in Figure Figure 2 Percentage of women in the investigation with this cause of infertility Key to causes of infertility A = Not ovulating B = Blocked oviducts C = Problems with uterus lining D = Woman over 40 years old E = Short menstrual cycle F = Unknown 10 A B C D E F Cause of infertility

7 7 Resource B Eggs that are used for IVF immediately after their collection are called fresh eggs. Eggs which are frozen and used later are called thawed eggs. Frozen eggs can be kept for several years before use. Table 1 show the outcomes of IVF from one clinic. All of the women in Table 1 were using their own eggs. Table 1 Age of women / years Percentage of women becoming pregnant after using fresh eggs Percentage of these pregnancies from fresh eggs that result in twins Percentage of women becoming pregnant after using thawed eggs Percentage of these pregnancies from thawed eggs that result in twins Below to to to Turn over

8 8 Section B Use the information in the Resource Sheet and your own knowledge to answer the questions. Answer all the questions in the spaces provided. Use Resource A to answer Questions 11 to What is IVF? [1 mark] 12 Describe and explain the evidence from Figure 2 that some women have more than one cause of infertility. 13 (a) The scientists only looked at causes of infertility in women who had never been pregnant before. Women who have had one child sometimes have difficulty getting pregnant with a second child. Suggest two reasons why the most likely cause is that they are over 40 years old

9 9 13 (b) IVF can help women who do not ovulate to get pregnant. Explain how. 14 Women with a short menstrual cycle have fewer days between ovulation and menstruation. This has been linked with infertility (block E on Figure 2). Suggest why. Use Resource B to answer Questions 15 and Use the data in Table 1 to describe how the outcomes of IVF treatment vary with age. Turn over

10 10 16 The head of the clinic stated that a 40-year-old woman had a better chance of becoming pregnant using a fresh egg than a thawed egg. Do the data in Resource B support this statement? Explain your answer. [3 marks] [Extra space]... Use Resource A and Resource B to answer Question All of the women with blocked oviducts in Figure 2 had IVF treatment using fresh eggs at the clinic in Resource B. All of these women were under 35 years. How many of them would you expect to have a successful pregnancy resulting in twins? Show your working. [3 marks] Answer END OF QUESTIONS

11 11 There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED

12 12 There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Copyright 2014 AQA and its licensors. All rights reserved.