CAIE A Level Biology 9700 · Inheritance
A plant species has a diploid chromosome number of 6 (2n = 6). During meiosis, both crossing over and random orientation of homologous chromosomes occur. Explain how these two processes contribute to the production of genetically different gametes. In your answer, compare the number of genetically different gametes that could be produced by random orientation alone with the number that could be produced by crossing over alone.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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