Answer: Begin to pair (synapsis starts).
- A Separate largely from their homologous partner
- B Undergo crossing over and exchange genetic material
- C Begin to pair (synapsis starts)
- D Largely condense into visible compact structures
Correct answer: C. Begin to pair (synapsis starts)
Explanation: Zygotene: homologous chromosomes begin to pair (synapsis) along their entire length, forming bivalents.
The cell cycle: G1 (growth and preparation), S (DNA replication, chromosome number stays 2n but DNA content doubles), G2 (final checks before division), and M (mitosis itself) - together, G1+S+G2 make up interphase.
Concept context
Mitosis and meiosis: how cells divide for growth, repair, and reproduction.