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Meiosis division

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Meiosis division

Postby ALevelBio » Mon Apr 09, 2012 12:39 pm

Hi, i am struggling to grasp the AS level meiosis concept. Now i know in Mitosis the DNA replicates so that we have 72 that divides into two cells with 46, which is two Diploid cells.

In meiosis i believe that DNA replication occurs, making 72 which then divides into 46 in two cells. These cells have the crossed over bivalent pairs. But from what i have read it is said that after this first division there are 2 haploid cells? How can this be if there are 2n chromosomes in each?
I need a helpful summary of what happens so i can understand!

Thanks
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Postby JackBean » Sat May 12, 2012 8:27 pm

There are two subsequent divisions with only one preceding replication. Thus, in the beginning you have 2n cell, replication -> 92 alleles -> 1st division = 46 alleles (2n) -> 2nd division = 23 alleles (1n)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
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