- A Sites of further chromosome condensation in metaphase
- B Crossing over (genetic recombination) in Prophase I
- C Points of spindle microtubule attachment to kinetochores
- D Sites of nuclear envelope breakdown in prophase
Correct answer: B. Crossing over (genetic recombination) in Prophase I
Explanation: Chiasmata are the X-shaped crossing points where homologous chromosomes have exchanged DNA. They hold bivalents together.
Concept context
Mitosis and meiosis: how cells divide for growth, repair, and reproduction.