Cell at metaphase of mitosis contains 20 sister chromatids, how many chromosomes will be present in a g1 cell? if a cell at metaphase of mitosis contains 20 sister chromatids, how many chromosomes will be present in a g1 cell? 10 40 20 5

The correct answer would be 10.

The cell cycle can be divided into four phases namely gap 1 (G₁) phase , synthesis (S) phase, gap 2 (G₂) phase, and  mitosis (M) phase.

DNA (deoxyribonuceic acid) content is only replicated and doubled in the S phase. However, the chromosome number remains the same. It can be explained as the number of chromosomes remains the same (2n) but number of chromatids doubles (4n) after S phase.

The number of chromatids restores to 2n in daughter cells after completion of mitosis.

Hence, if number of chromatids in metaphase was 20 i.e. 4n then the number of chromosomes (2n) would be 10.

Hence, 10 chromosomes or 5 pairs of chromosome would be present in the cell during its G₁ phase.