What must happen before crossing over can occur in meiosis

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

answer; the male's sperm cells have mitochondria, but because the sperm contributes dna but no cytoplasm, no mitochondria are passed to the egg at ferilization;