Question

During which stage of mitosis do chromosomes duplicate?

Answer 1

Genetic material replicates before mitosis, during the interphase.

Explanation:

DNA replication (and thus chromosome duplication) occurs during the interphase , the part of the cell cycle in which the cell is not dividing. It is important to know that the interphase is not part of mitosis.

Here is your typical cell cycle:

As shown here, DNA replicates during the S phase (synthesis phase) of interphase, which is not part of the mitotic phase. When DNA replicates, a copy of each chromosome is produced, so chromosomes duplicate.