Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Problem:Passage: Prophase I: Chromosomes form, and the nuclear membrane breaks down. Centrioles move to opposite poles of the cell. Spindle fibers form between the centrioles. Here's what's special about meiosis : Homologous chromosomes pair up! You can see this in Figure below . Answer: meiosis
Solution:
Spindle fibers form between the centrioles during prophase i of what process?