In oogenesis, first polar body is formed after_____ during the division of_________.
In oogenesis, first polar body is formed after_____ during the division of_________.
The correct option is A meiosis I, primary oocyte
Oogonia undergo mitosis during the first three months of fetal development producing all the 2 million primary oocytes which are arrested at prophase I.
These primary oocytes remain in this state till puberty. However, out of these only 60,000 to 80,000 survive till puberty while the rest degenerate.
At the onset of puberty, meiosis resumes. The primary oocyte completes meiosis I which results in a secondary oocyte and a tiny first polar body. The secondary oocyte starts to divide but gets arrested in metaphase of meiosis II.
The secondary oocyte completes its meiotic division only after the sperm binds to it. The division of the secondary oocyte results in the formation of a second polar body and ovum.
Hence the first polar body is formed after meiosis I during the division of primary oocyte.
Oogonia undergo mitosis during the first three months of fetal development producing all the 2 million primary oocytes which are arrested at prophase I.
These primary oocytes remain in this state till puberty. However, out of these only 60,000 to 80,000 survive till puberty while the rest degenerate.
At the onset of puberty, meiosis resumes. The primary oocyte completes meiosis I which results in a secondary oocyte and a tiny first polar body. The secondary oocyte starts to divide but gets arrested in metaphase of meiosis II.
The secondary oocyte completes its meiotic division only after the sperm binds to it. The division of the secondary oocyte results in the formation of a second polar body and ovum.
Hence the first polar body is formed after meiosis I during the division of primary oocyte.
(a) About 300 million spermatozoa may be present in a human male ejaculation at one time. Calculate how many spermatocytes will be involved to produce this number of spermatozoa.
