How is the timing of gamete formation in females different than that in males? What will be an ideal response?
ANSWER: In males, spermatogenesis begins at puberty and takes about 48 days: 16 for meiosis I, 16 for
meiosis II, and 16 to convert the spermatid into the mature sperm. Each of the four products
of meiosis forms sperm.
The timing of gamete formation in females is much different than in males. In oogenesis,
cells in the ovaries (called oogonia) begin meiosis I during embryonic development and then
stop. After puberty, usually one oocyte per menstrual cycle completes the first meiotic
division, is released from the ovary, and moves into the oviduct. Fertilization takes place in
the oviduct. Fertilized eggs quickly complete meiosis II, producing a diploid zygote.
Unfertilized eggs disintegrate within 24 hours after ovulation. Each month until menopause another oocyte completes meiosis I and is released from the ovary. Altogether, a woman
produces and releases about 450 oocytes during the reproductive phase of her life.
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