A-Level BiologyYear 2022Q5
12 5 (a) The photograph shows a germinating pollen grain as seen through a light microscope. (Source: © CAROLINA BIOLOGICAL SUPPLY COMPANY/SCIENCE PHOTO LIBRARY) The actual length of this pollen tube is 136 µm. Calculate the magnification of this photograph. (2) Answer .............................................................. Turn over 13 (b) (i) The diagram shows a pollen grain that has begun to germinate after landing on the surface of the stigma of a flower. wall of pollen grain B A pollen tube top of stigma cytoplasm Identify the structures labelled A and B. (2) A ............................................................................................................................................................................................................................................................................... B ............................................................................................................................................................................................................................................................................... (ii) Describe the process of double fertilisation in flowering plants. (3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 14 (c) Devise an investigation to determine the effect of pH on the rate of growth of pollen tubes. 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(Total for Question 5 = 12 marks)
Paper Source:9bi0-03-que-20220625.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)
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