At metaphase stage of meiosis the number of chromatids in each chromosome is a.2 b.1 c.3 d.4

Dear student,

There are two divisions during meiosis: meiosis I and meiosis II. During S phase of interphase there is duplication of the genetic material of the cell, just as it was with mitosis resulting in 46 chromosomes and 92 chromatids during Prophase I and Metaphase I.

let us look at the hypothetical 2n=8 cell during metaphase I. 

You may expect the chromosome number to change when Anapahse I begins, but it does not. The chromosome number changes only after the sister chromatids separate. Since only the homologus chromosomes separate in Anaphase I, neither the chromosome number nor the chromatid number changes during anaphase.

The chromosome number or the chromatid number does not change due to the separation of the homologus chromosomes. There are still 8 chromosomes and 16 chromatids. In fact, until the completion of meiosis I, the chromosome and chromatid numbers remain the same through all stages. Similarly in a human, there is no change in the chromatid or the chromosome number until meiosis I.

The meiosis II appears similar to mitosis, with the only difference being that there are now half as many chromosomes as before. Continuing with the 2n=8 cell example from above, we will observe a cell during metaphase II:

The chromosomes are lined up individually across the center of the cell, during metaphase II. Due to the reduction division of meiosis I, there are now half as many chromosomes (and chromatids) as there were before. When anaphase II begins, however, the sister chromatids split apart, which once again doubles the chromosome number

*Notice that the chromatid count never changes during the stages of Mitosis and Meiosis. Only the number of chromosomes changes (by doubling) when sister chromatids are separated during Anaphase. During Meiosis I, until after telophase I is complete neither the chromosome number nor the chromatid number changes.

Regards.