A-Level BiologyYear 2021Q2
4 2 Children are different from their parents due to genetic variation and other factors. Genetic variation can be the result of meiosis and random fertilisation of gametes. (a) Describe how meiosis leads to genetic variation in the gametes produced. 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(b) During random fertilisation, only one sperm cell fuses with the cell surface membrane of an egg cell. Vesicles play an important role in this process. Explain how vesicles are involved in the successful fertilisation of an egg cell by only one sperm. 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Turn over 5 (c) Variation between children and their parents is affected by linkage of genes. Explain why some genes show linkage and others show sex-linkage. 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(Total for Question 2 = 7 marks)
Paper Source:9BN0_02_que_20211016.pdf
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Exam Specification Info
This question is part of the UK A-Level Biology syllabus. In the actual exam, structured questions typically require linking specific keywords to gain full marks. Applaa helps you drill these topics.
Syllabus levelAdvanced Level (A-Level)
SubjectBiology
Official MarksVariable (2–6 marks)