What happens during crossing over?

During crossing over, homologous chromosomes exchange DNA segments, which occurs during prophase I of meiosis. This process is crucial for genetic diversity, as it allows for new combinations of alleles to form on each chromosome. When homologous chromosomes align closely together, they can break and rejoin to trade segments. This exchange of genetic material creates recombinant chromosomes, contributing to variations in the traits of offspring.

The other options do not accurately describe crossing over. Chromosomes duplicating refers to the process that occurs before meiosis begins, while random sorting involves the independent assortment of chromosomes rather than the exchange of genetic material between them. Gametes formed with the same genetic material do not reflect the genetic diversity introduced by crossing over, as crossing over specifically leads to different genetic combinations.