Following mitosis, a cell is said to contain 1 sister chromatid (separated from sister chromatid pair) . How is this cell still considered diploid? How is this cell considered to have 2n chromosomes? How is this cell said to have 2 copies of each gene, and therefore 2 alleles? mitosis

mitosis

The fact that a cell is considered diploid after mitosis can be explained by the nature of the sister chromatid. During mitosis, the chromosomes separate and form two identical copies of the original chromosome, known as sister chromatids. These sister chromatids still contain the same DNA as the original chromosome, so the cell is still considered diploid because it contains two sets of chromosomes. Therefore, the cell is still considered to have 2n chromosomes, where n is the haploid number of the species. Furthermore, the sister chromatids are exact copies of the original chromosome, so this cell still has two copies of each gene, and therefore two alleles. Since the sister chromatids have the same sequence of nucleotides, this means that the cell is still considered diploid, with two copies of each gene, and therefore two alleles. This is important for genetic variation, as it means that the cell is capable of expressing different traits due to the two different alleles (Lai et al., 2016). Cont…