Why is crossing over during meiosis important for genetic variation?

• A. It prevents mutations from occurring during cell division.
• B. It ensures that each gamete receives an identical set of chromosomes.
• C. It allows for the exchange of genetic material between homologous chromosomes, increasing genetic diversity.
• D. It reduces the number of chromosomes in the gametes by half.

Answer: (C)

Verified step by step guidance

1. Understand the process of meiosis: Meiosis is a type of cell division that reduces the chromosome number by half, creating four haploid cells, each genetically distinct from the parent cell. It consists of two consecutive divisions: meiosis I and meiosis II.
2. Learn about homologous chromosomes: Homologous chromosomes are pairs of chromosomes, one from each parent, that are similar in shape, size, and genetic content. During meiosis, these pairs line up closely together.
3. Explore the concept of crossing over: Crossing over occurs during prophase I of meiosis I, where homologous chromosomes exchange segments of genetic material. This process is facilitated by the formation of a structure called the synaptonemal complex.
4. Recognize the importance of genetic variation: Crossing over results in new combinations of alleles on each chromosome, contributing to genetic diversity in the offspring. This genetic variation is crucial for evolution and adaptation in populations.
5. Distinguish crossing over from other processes: Unlike mutation prevention or chromosome reduction, crossing over specifically increases genetic diversity by allowing the exchange of genetic material between homologous chromosomes.