In human females, when does meiosis II occur?
A. at ovulation
B. immediately after the sperm penetration of the secondary oocyte
C. immediately after the aperm penetrates the primary oocyte
D. None of the choices are correct
- Bob D1Lv 71 decade agoFavourite answer
B.) Is the correct answer.
"Mature (Graafian) Follicle -- ... large, fluid-filled follicle .... ruptures and expels a secondary Oocyte."
"Secondary Follicle -- After the granulosa cells begin to secrete follicular fluid, ... Meiosis-1 resumes in several secondary Oocytes, ... The diploid primary Oocyte completes meiosis-1, resulting in two haploid cells of unequal size,... The smaller cell produced by meiosis-1, ... First Polar Body, is essentially ... discarded nuclear material; the larger cell, ... Secondary Oocyte, receives most of the cytoplasm. Once a secondary Oocyte is formed, it begins meiosis-2 and then stops."
The secondary Oocyte only completes meiosis-2 only after the sperm cell has successfully fertilized the egg. This triggers the formation and displacement of the second polar body to the surface of the fertilized egg cell.Source(s): self
- 1 decade ago
No, sorry, that answer was wrong. Meiosis II occurs before sprem penetration. It must be A then...Meiosis II comes after the seconday oocyte, and that happens after an egg is released. But I don't think Meiosis II happens AT ovulation.
I would say A because "None of the above" is never the right answer. And A sounds right because I guess it actually does happen at ovulation. The reason Meiosis II doesn't finish is because it doesn't become fertilized, so I'd say A
For the answer below, Mitosis is what makes the eggs. Meiosis II happens after the egg is released into the uterus.
- FaithLv 44 years ago
It does make four cells. Three of them are called polar bodies, and are essentially just little garbage bags to hold the extra unwanted chromosomes. They have almost no cytoplasm. The reason for doing this seems to be to make the egg cell as large as possible. The larger it is, the more raw materials are there to begin the process of growing from one cell into a baby.
- 1 decade ago
Not A i think D
- What do you think of the answers? You can sign in to give your opinion on the answer.
- Anonymous1 decade ago
hm, I'm not sure