What is the outcome of crossing over during meiosis?

• A. Crossing over results in identical gametes
• B. Crossing over leads to genetic recombination, increasing genetic diversity
• C. Crossing over produces two diploid cells
• D. Crossing over is a process that only occurs in mitosis

Answer: (B)

The correct outcome of crossing over during meiosis is that it leads to genetic recombination, which increases genetic diversity. During the prophase I stage of meiosis, homologous chromosomes undergo a process called synapsis, where they align closely along their lengths. This close alignment facilitates the exchange of genetic material between non-sister chromatids of homologous chromosomes. This exchange results in new combinations of alleles on the chromosomes, producing gametes that are genetically distinct from one another and from the parental gametes. This genetic diversity is crucial for evolution and adaptability in populations.

Other options do not accurately reflect the outcome of crossing over. Identical gametes would not arise from crossing over; rather, the recombinant chromosomes contain a mix of genetic information from both parent chromosomes, leading to variations. The production of diploid cells is not directly related to crossing over since meiosis results in haploid gametes, not diploid cells. Finally, crossing over is a specific process that occurs during meiosis, not mitosis, where sister chromatids simply separate without the exchange of genetic material.