Different cyclins peak at different cell-cycle stages and pair with their CDK partners.
Cyclin D-CDK4/6 primarily drives:
- A
Mitotic entry at G2/M
- B
Chromosome segregation
- Ccheck_circle
Progression through G1 toward S phase
- D
Apoptosis
Explanation
Cyclin D rises early in G1; binding CDK4/6 inactivates Rb (retinoblastoma) protein, releasing E2F transcription factors and promoting entry into S phase.