Optometry Admission Test (OAT) Practice

Crossing over during meiosis is a significant process that contributes to increased genetic variation among offspring. This event occurs during prophase I of meiosis when homologous chromosomes pair up and exchange segments of genetic material. This exchange results in new combinations of alleles on each chromosome, which means that the gametes produced will have different genetic configurations compared to those of the parents.

As a result, when fertilization occurs, the resulting offspring will show a blend of traits from both parents, enhancing genetic diversity within a population. This variation is crucial for evolutionary processes and adaptation to changing environments.

The other options, while related to meiosis, do not specifically capture the essence of crossing over. For example, the formation of sister chromatids occurs during DNA replication prior to meiosis, not as a direct result of crossing over. Similarly, while crossing over contributes to the development of gametes, this process encompasses more than just genetic recombination. Lastly, the duplication of chromosomes refers to the replication process that happens before meiosis begins and is unrelated to the specific function of crossing over itself.