daytrippper
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Can someone explain meiosis to me? I've memorised all the steps but I don't fully understand it? + can anyone explain independent segregation and crossing over?
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Bookaddict02
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wasnt this in bio paper 1 which is already done.
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kapowginger
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(Original post by daytrippper)
Can someone explain meiosis to me? I've memorised all the steps but I don't fully understand it? + can anyone explain independent segregation and crossing over?
OK so the importance of meiosis is that it gives rise to genetic variation, as each of the four daughter cells (haploid/gametes) are genetically unique (not identical to neither each other nor the parent cells).

I think independent assortment is the idea that it is random which side of the equator each homologous chromosome (of a homologous chromosome pair) goes, so either homologous chromosome may eventually end up at either pole of the cell (and thus daughter cell) in a completely random way. Anyone please correct me on that if that's not right.

Crossing over however (also in meiosis i - metaphase i), is when the homologous chromosomes pair up. Here, they essentially squeeze tightly over each other and exchange parts of DNA at the same loci (position on the chromosome). This forms 'chiasmata' or recombinant chromosomes, so the genetic material/alleles on each of the homologous chromosomes is now mixed from mum and dad, because of the exchange in crossing over.

I hope that makes sense and like I said, if any of that isn't quite right let me know!
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