The reciprocal exchange of chromatids during meiosis is called
- A. Synapsis
- B. Crossing over
- C. Diakinesis
- D. Terminalization
Answer: B. Crossing over
- Occurs during prophase I of meiosis, when homologous chromosomes (chromosomes that carry similar genes from each parent) pair up.
- Involves the physical exchange of genetic material between non-sister chromatids (the two copies of each chromosome) of the homologous pair.
- This exchange happens when synapsis, the close pairing of homologous chromosomes, brings them together at specific points called chiasmata.
- At the chiasmata, the chromatids break and then rejoin, but this time, they rejoin with the corresponding chromatid from the other homologous chromosome.