10.1 Meiosis

Genetic variety

If we look at the example with just two chromosomes we can see that at metaphase I the chromosomes can be randomly arranged in four (22) possible ways.

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If we did the same combination logic with three chromosomes we would have eight (23)possible combinations. If we look at 23 chromosomes as in human cells we will have (223) possible combinations. This means we can have an almost infinite variety of gametes. If we add in random crossing over at any point in the chromosome we will effectively have this infinite variety.

The pairing up shown above could lead to many different combinations of crossing overs during prophase I. Some of which are shown below.image

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HL Topic 10 Genetics Copyright © by Alex Black. All Rights Reserved.

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