During which phase of meiosis do chromosome pairs line up along the cell equator? This arrangement allows for chromosomal combination. What do these chromosomal rearrangements cause?

This phase is metaphase, and you can remember this by seeing the m means middle.

The chromosomal combination allows for each sex cell that is going to be produced to have different DNA combinations, allowing for the offspring to be not only different from the parents, but also allows for genetic diversity.