Why is secondary spermatocyte a haploid cell?

[scilearner]

Hello everyone,

 

Ok I know it has 23 chromosomes. But they are double structured chromosomes, so can you still call them haploid. Also spermatids, can you call them haploid cells. You can't right because they haven't matured.

[Genecks]

Haploids have half the number of chromosomes a diploid has.

*closes book*

[scilearner]

But secondary spermoctye have 23 double structured chromosomes. That means potentially 46 chromosomes.

Edited December 8, 2010 by scilearner

[Guest davidmlee]

Secondary spermatocyte one of the two haploid cells into which a primary spermatocyte divides, and which in turn gives origin to spermatids.

 

 

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David Lee

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[jimmydasaint]

But secondary spermoctye have 23 double structured chromosomes. That means potentially 46 chromosomes.

 

I think you mean 46 chromatids. In contrast, the primary spermatocyte would have 92 chromatids. Finally, a spermatid would have 23 chromatids.

 

Let's keep it simple. We start off with a diploid cell with 46 chromosomes (2n=46) and, at the secondary spermatocyte end up with 23 chromosomes. Finally, these double X-like structures divide into two halves, but are still called haploid. Compare them to the germ cell that kicks off the meiosis.

 

The germ cell has what you would call 46 single structured chromosomes, but the spermatid has 23 single structured chromosomes.

 

The links have a good explanation:

Spermatogenesis diag

 

Meiosis

 

(I am trying to avoid Wikipedia because of Jimmy Wales' begging eyes that reminds me of a Springer Spaniel begging its owner to go for a walk - I just can't resist those Wales' eyes and I want to donate to Wiki every time).

Edited December 20, 2010 by jimmydasaint