What occurs in crossing over:
1.  Recombination
2.  Mutation
3.  Independent assortment
4.  None

Amount of cellular DNA increases during:

Crossing over that results in genetic recombination in higher organisms occurs between:
1. Non-sister chromatids of a bivalent
2. Two daughter nuclei
3. Two different bivalents
4. Sister chromatids of a bivalent