Crossing over occurs between homologous chromosomes.Group of answer choicesmitosis onlyneither mitosis nor meiosismeiosis onlyboth mitosis and meiosisNext

Understanding the Concept of Crossing Over

Crossing over is a crucial biological process that occurs during cell division. It involves the exchange of genetic material between homologous chromosomes, which are pairs of chromosomes that contain the same genes but may have different alleles.

Examining the Options

1. Mitosis Only: Mitosis is responsible for cell division in somatic (non-reproductive) cells, and it does not involve crossing over. Therefore, this option is not correct.

2. Neither Mitosis Nor Meiosis: This option can be dismissed because we know crossing over occurs during meiosis.

3. Meiosis Only: Meiosis is specifically the type of cell division that reduces the chromosome number by half and generates gametes (sperm and eggs). Crossing over occurs here during prophase I, making this option a strong candidate.

4. Both Mitosis and Meiosis: As established, crossing over does not occur in mitosis. So, this option is also incorrect.

Conclusion

Upon analyzing the choices, the correct answer is meiosis only. This is the specific process where crossing over occurs between homologous chromosomes, contributing to genetic diversity in gametes.