Answer:
Because chromosomes are highly condensed during mitosis
Explanation:
Chromosomes are structures of packed and organized DNA molecules together with proteins. They are only visible under a light microscope only when the cell is undergoing the metaphase of cell division ( aligned in the center-metaphase plate). In this phase chromosomes are in their condensed form and easiest to distinguish and study.
DNA replication occurs during the S phase of interphase, which is the phase before cell division.
