Meiosis occurs in a series of different phases and creates genetically unique reproductive cells. Which process helps make meiotic cells genetically different and occurs during prophase I, but not during prophase II?

During prophase I, homologous chromosomes pair up and can exchange matching segments of DNA, a process called crossing over. This creates new combinations of genes in the resulting reproductive cells. Crossing over does not occur in prophase II, so the correct choice is crossing over.

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