Which statement best explains the relationship between crossing over and genetic variation during meiosis?

• A. Crossing over eliminates mutations from the genome, thereby reducing genetic variation.
• B. Crossing over exchanges genetic material between homologous chromosomes, creating new allele combinations and increasing genetic variation in gametes.
• C. Crossing over ensures that each gamete receives a complete set of chromosomes, but does not affect genetic variation.
• D. Crossing over only occurs in mitosis and does not contribute to genetic variation.

Answer: (B)

Verified step by step guidance

1. Understand that crossing over is a process that occurs during prophase I of meiosis, where homologous chromosomes pair up and exchange segments of their genetic material.
2. Recognize that this exchange results in new combinations of alleles on each chromosome, which are different from the original parental chromosomes.
3. Recall that these new allele combinations increase genetic variation among the gametes produced, which is important for evolution and adaptation.
4. Note that crossing over does not eliminate mutations; rather, it reshuffles existing genetic information to create diversity.
5. Conclude that the key relationship is that crossing over increases genetic variation by exchanging genetic material between homologous chromosomes during meiosis.