Separation of first polar body occurs at the time of: September 2007, March 2012
Ans. B: Ovulation Asymmetrical cell division (cytokinesis) leads to the production of polar bodies during oogenesis. To conserve nutrients, the majority of cytoplasm is segregated into either the secondary oocyte and, or ovum, during meiosis I or meiosis II, respectively. The remaining daughter cells generated from the meiotic events contain relatively little cytoplasm and are referred to as polar bodies. Eventually, the polar bodies degenerate. There may be one or two polar bodies in the ovum. The first polar body is one of the two products in the first stage of meiosis, just before ovulation and is considered diploid, with 23 duplicated chromosomes. The second polar body is haploid, with 23 unduplicated chromosomes and is produced only when a sperm penetrates the oocyte.
Feilization
Ovulation
Implantation
Menstruation