AP BIOLOGY

Detailed explanation-1: -Meiosis is necessary for sexual reproduction to occur, as it results in the formation of gametes (sperm and eggs). However, sexual reproduction includes fertilization (the fusion between gametes), which is not part of the meiotic process.

Detailed explanation-2: -Fertilization and completion of meiosis. (A) Fertilization induces the transition from metaphase II to anaphase II, leading to completion of oocyte meiosis and emission of a second polar body (which usually degenerates).

Detailed explanation-3: -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-4: -This would lead to many genetic disorders and developmental defects. Hence meiosis should occur before fertilization to maintain the number of chromosomes in the zygote and prevent chromosomal defects in the offspring.

Detailed explanation-5: -When egg and sperm form, they go through a special type of cell division called meiosis. One purpose of meiosis is to reduce the number of chromosomes by half. The other is to create genetic diversity. Meiosis begins like mitosis: the cell copies each chromosome.