Which of the following occurs during crossing over in meiosis?

• A. Formation of the mitotic spindle
• B. Separation of sister chromatids
• C. Exchange of genetic material between homologous chromosomes
• D. Replication of DNA

Answer: (C)

Verified step by step guidance

1. Understand that 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.
2. Recognize that crossing over is a crucial event that occurs during prophase I of meiosis. It involves the exchange of genetic material between homologous chromosomes.
3. Identify homologous chromosomes as pairs of chromosomes, one from each parent, that are similar in shape, size, and genetic content.
4. During crossing over, homologous chromosomes pair up and exchange segments of their genetic material. This process increases genetic diversity by producing new combinations of alleles.
5. Note that the other options listed (formation of the mitotic spindle, separation of sister chromatids, and replication of DNA) are not associated with crossing over. The mitotic spindle forms during mitosis, sister chromatids separate during anaphase II of meiosis, and DNA replication occurs during the S phase of the cell cycle, prior to meiosis.