SuperSaiyan3

7+ Year Member
May 13, 2009
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This is in regards to spermatogenesis.

When does the diploid (46 chromosome) sperm become a haploid?

From my physiology notes, I've got the process as:

1. spermatogonia (diploid = 46 chromosomes) undergoes cell division to primary spermatocyte (still diploid).
2. P. sperm undergoes meiosis I to secondary spermatocyte (still diploid = 46 chromosomes).
3. S. sperm undergoes meiosis II to spermatid (now my sperm is haploid = 23 chromosomes).

BUT. In accordance with wikipedia's notions:

"In spermatocytogenesis, a diploid spermatogonium which resides in the basal compartment of seminiferous tubules, divides mitotically to produce two diploid intermediate cell called a primary spermatocyte. Each primary spermatocyte then moves into the adluminal compartment of the seminiferous tubules and duplicates its DNA and subsequently undergoes meiosis I to produce two haploid secondary spermatocytes."

Wikipedia pretty much says that the gene count goes down to 23 at the SECONDARY spermatocyte, which contradicts my notes.

Can anybody verify this?

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- SS3 :luck:
 
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SuperSaiyan3

SuperSaiyan3

7+ Year Member
May 13, 2009
356
4
Status
1. spermatogonia (diploid = 46 chromosomes) undergoes cell division to primary spermatocyte (still diploid).

- 46 chromosomes: 92 chromaTIDs


2. P. sperm undergoes meiosis I to secondary spermatocyte (becomes haploid = 23 chromosomes).

- 23 chromosomes : 46 chromaTIDs

3. S. sperm undergoes meiosis II to spermatid (still haploid= 23 chromosomes).

- 23 chromosomes: 23 chromatids
Boo-ya.

Just answered my own question. Turns out I was confused by the difference between CHROMOSOMES and CHROMATIDS. Better watch out for this terminology on test day kids. The MCAT Boogie-Man will get you...

you're welcome. :luck: