Enumerate the stages of normal spermatogenesis.
Answer:
The cell stages in spermatogenesis are as follows.
- The spermatogonia (type A) or germ cells.
- Type A cells divide mitotically.
Result: More spermatogonia type A and also spermatogonia type B.
No. of chromosome: 44+X+Y.
- Type A cells divide mitotically.
- The spermatogonia (type B).
- They enlarge or undergo mitosis.
Results: Formation fof primary spermatocytes.
No. of chromosome: 44 + X + Y
- They enlarge or undergo mitosis.
- The primary spermatocytes (44+ X + Y)
- They divide so that each forms two secondary spermatocytes.
- It is first meiotic division.
- No. of chromosome: Reduced to half, 22+ X or 22+ Y
- Secondary spermatocytes.
- It divides to form two spermatids.
- It is second meiotic division.
- No. of chromosome: 22+ X or 22+ Y
- Spermatid.
- It gradually changes its shape to form spermatozoon.
- It is called spermiogenesis.
- No. of chromosome: 22+ X or 22 +Y.
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Time period:
It takes about two months for the completion of the process.
Results: Spermatids are formed.
- They are more or less circular cell.
- They contain.
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- Nucleus forming head.
- Golgi apparatus – transforms into acrosomic cap.
- Centriole divides into two parts.
- One becomes spherical and lie in neck.
- The remaining part elongates to form tail.
- Mitochondria.
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