Question

In human cell undergoing mitosis,how many chromosomes are present in prophase,metaphase,anaphase and telophase?

please help me.. >.<

Answer

In prophase, there are 46 condensed chromosome pairs. The chromosomes replicated during S phase (Doubling the original 23 pairs) and now appear as two sister chromatids connected via the centromere. During metaphase, the kinetochores of the chromatids attach to the spindle fibers and the chromosomes have now moved into position along the metaphase plate (an imaginary division) and are roughly central in the cell. During anaphase the spindles begin pulling the chromatids apart from one another and telophase begins. During telophase, the nuclear envelopes of the cells to be forms. At this point it's a tad murky as the chromosomes are clearly separated but the cell has not yet made a complete divide. The division completes during cytokinesis beginning with the formation of a cleavage furrow will separate the cytoplasm and eventually yields two daughter cells. At this point the cell will have 23 chromosome pairs.

The above is only true if we are talking about a somatic cell. If we are talking about a sex cell i.e a sperm or an egg then after the first meiotic division, there will be another one that follows the same processes as the first, only this time without the luxury of having undergone the replication during S phase and as such once cytokinesis finishes there will only be 23 single chromosomes in the given sex cell.

So I would say 92 total chromosome from S phase to cytokinesis 1 of meiosis 1. and after cytokinesis 46 with the addendum that if we are discussing a sex cell and not a somatic cell it will then begin meiosis 2 carrying the 46 chromosomes through until after cytokinesis at which point it will only have 23 single chromosomes.

Jul 9 at 4:46

During mitosis the cell remain with 46 chromosomes. Only chromatid numbers are changed. It became doubled. Each chromosome has 2 chromatids. In prophase the chromatid numbers doubled and at last when the cell divided in to two then each cell contain 46 chomosom as well as same number of chromatid.

Jul 9 at 8:32