MICROANATOMY

Detailed explanation-1: -After ovulation the oocyte is arrested in metaphase of meiosis II until fertilization. At fertilization, the secondary oocyte completes meiosis II to form a mature oocyte (23, 1N) and a second polar body .

Detailed explanation-2: -Meiosis occurs in the primordial germ cells, cells specified for sexual reproduction and separate from the body’s normal somatic cells. In preparation for meiosis, a germ cell goes through interphase, during which the entire cell (including the genetic material contained in the nucleus) undergoes replication.

Detailed explanation-3: -During meiosis II, the duplicated chromosomes are separated into a polar body and a mature ovum. At this point, the haploid nuclei of the egg and sperm are able to fuse to form the zygote. Therefore, when meiosis II is completed is given by answer choice (A): after a secondary oocyte has been fertilized.