During which phase is genetic variation introduced in plants and animals?

Genetic variation is primarily introduced during Prophase I of meiosis. During this phase, a process called homologous recombination or crossing-over occurs. This involves the exchange of genetic material between homologous chromosomes, leading to new combinations of alleles. As a result, the gametes produced through meiosis contain different genetic information from each parent, which contributes to genetic diversity in the offspring.

While Telophase II marks the completion of meiosis and the final separation of daughter cells, it does not play a role in introducing genetic variation. Anaphase I is primarily responsible for the separation of homologous chromosomes, but it is during Prophase I that the actual exchange of genetic material occurs. Interphase, on the other hand, is the phase where the cell prepares for division and does not involve the specific mechanisms that increase genetic diversity.