AP BIOLOGY

Detailed explanation-1: -Crossing over between chromatids can occur only between homologous chromosomes. While the maternal and paternal chromosomes are separating, the chromatid material very often gets exchanged between two members of the homologous pair resulting in genetic recombination during the meiotic cell division.

Detailed explanation-2: -Crossing over occurs between prophase I and metaphase I and is the process where two homologous non-sister chromatids pair up with each other and exchange different segments of genetic material to form two recombinant chromosome sister chromatids.