What are the number of (human) chromosomes in each stage of Meiosis?
1 Answer
Meiosis is divided in M I and M II. In the beginning of M I, one germ mother cell has 46 chromosomes, and at the end of M II, each of the generated four gametes will possess only 23 chromosomes.
Explanation:
Before meiosis starts, the mother cell has the complete 2n set that is, 23 pair/46 chromosomes in its nucleus : Each chromosome is represented twice in the full set (as homologous pair) and each chromosome is with two chromatids joined at centromeric region.
During meiosis I, the homologous chromosomes separate and reach opposite poles. Thus two new cells are generated after M I, each with half of the chromosomes that the mother cell had, i.e. 23 , though each chromosome still possesses double chromatids.
Each of the newly generated cells with half the number of chromosomes divide during meiosis II and thus four gametes are generated. This time chromatids separate and move towards opposite poles. Each gamete possesses only 23 chromosomes at the end of M II but now the each chromosome is with only a single chromatid .
