meiosis I vs II

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xbeautifuldisasterx3
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meiosis I vs II

Post by xbeautifuldisasterx3 » Sun Jan 29, 2006 6:43 pm

whats the difference between them?!

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Dr.Stein
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Post by Dr.Stein » Mon Jan 30, 2006 8:38 am

Meiosis I = Half reduction, e.g. diploid ---> haploid
Meiosis II = Mitosis, e.g. haploid --->haploid
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sdekivit
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Post by sdekivit » Mon Jan 30, 2006 8:58 am

Dr.Stein wrote:Meiosis I = Half reduction, e.g. diploid ---> haploid
Meiosis II = Mitosis, e.g. haploid --->haploid


to give an example to make it more clear:

we have a diploid cell with an allele for blue eyes and brown eyes. In meiosis 1 the DNA doubles and homologgues chromosomes come together and they separate

--> thus: blue will go to one cell (2 alleles) en brown goes to the other cell (2 alleles)

--> these cells have normal amount of DNA, but contain only 1 allele and are thus haploid.

Next, in meiosis 2, the amount of DNA halves and it's just like a mitosis.

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Dr.Stein
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Post by Dr.Stein » Mon Jan 30, 2006 9:42 am

A simple figure to complete sdekivit's explanation: ;)
(click the image for full-size view)

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M.Shanti Priya
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Post by M.Shanti Priya » Thu Feb 02, 2006 9:32 am

Meiosis I is the reductional division - chromosome number is reduced but not the DNA content and each chromosome has 2 chromatids.
Meiosis II the chromatids are separated and hence the DNA content also.

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