Florida Biology EOC Practice Test

What occurs during anaphase of mitosis?

1. Chromosomes become visible

2. Chromosomes are pulled apart

3. Sister chromatids align at the cell center

4. The nuclear membrane reforms

The correct answer is: Chromosomes become visible

During anaphase of mitosis, the key event is that the sister chromatids are pulled apart and moved toward opposite poles of the cell. This separation is crucial for ensuring that each daughter cell receives an identical set of chromosomes. The chromosomes, which have already been duplicated and are tightly coiled, are split at the centromere during this phase. The visibility of chromosomes occurs earlier in the process, during prophase, when they condense and become distinguishable. The alignment of sister chromatids at the cell center happens during metaphase, prior to anaphase. The reformation of the nuclear membrane occurs later, during telophase, once the chromosomes have been successfully separated and are moving towards the poles. Thus, the correct identification of anaphase is centered around the separation and movement of sister chromatids.