AP BIOLOGY

Detailed explanation-1: -At the onset of puberty, the primary oocyte (2n) undergoes the first meiotic division. This results in the formation of the secondary oocyte (n). Secondary oocytes start undergoing second meiotic division but get arrested at metaphase II; until they meet the sperm in the fallopian tube.

Detailed explanation-2: -At puberty, meiosis resumes. One cell at the end of meiosis I enters meiosis II each month. The result of meiosis II is a single egg cell per cycle (the other meiotic cells disintegrate).

Detailed explanation-3: -Meiosis during spermatogenesis is specific to a type of cell called spermatocytes, which will later mature to become spermatozoa. Meiosis of primordial germ cells happens at the time of puberty, much later than in females.

Detailed explanation-4: -These latter cells, called the primary oocytes, progress through the first meiotic prophase until the diplotene stage, at which point they are maintained until puberty.

Detailed explanation-5: -Meiosis is the unique division of germ cells resulting in the recombination of the maternal and paternal genomes and the production of haploid gametes. In mammals, it begins during the fetal life in females and during puberty in males.