Question

during which phase does nondisjunction typically occur? prophase i metaphase ii telophase i anaphase ii

Explanation:

Nondisjunction, the failure of chromosomes to separate properly, typically occurs during anaphase (either anaphase I or anaphase II). Among the options, anaphase II is a phase where sister chromatids should separate, and nondisjunction can happen here as chromosomes may fail to move to opposite poles. Prophase I is about crossing over, metaphase II is alignment, and telophase I is about nuclear envelope reformation, so anaphase II is the correct choice.

Answer:

anaphase II