Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: A mitotic spindle forms from the centrioles and passes through the nuclear membrane, which remains intact. Chromosomes attach to the mitotic spindle, which separates the chromosomes and elongates the cell. Answer: elongates the cell
A:
A mitotic spindle forms from the centrioles and passes through the nuclear membrane, which remains intact. chromosomes attach to the mitotic spindle, which separates the chromosomes and does what?