NEETBotanyCell Cycle and Cell Division
Read the following cellular events carefully: X: Centriole duplicates in the cytoplasm of animal cells. Y: Proteins are synthesized in preparation for mitosis. Z: Cells remain metabolically active but no longer proliferate unless called on to do so. Identify the cell cycle phases corresponding to the events X, Y, and Z respectively.
Options
- AX - G₂ phase, Y - S phase, Z - G₁ phase
- BX - S phase, Y - G₁ phase, Z - G₀ phase
- CX - S phase, Y - G₂ phase, Z - G₀ phase
- DX - G₁ phase, Y - G₂ phase, Z - G₀ phase
Correct answer
C. X - S phase, Y - G₂ phase, Z - G₀ phase
Step-by-step solution
Event X corresponds to the S phase (synthesis phase). During this phase, DNA replication occurs in the nucleus, and the centriole duplicates in the cytoplasm of animal cells. Event Y corresponds to the G₂ phase. During the G₂ phase, proteins are synthesized in preparation for mitosis while cell growth continues. Event Z corresponds to the G₀ phase (quiescent stage). Cells in this stage exit the G₁ phase and enter an inactive stage where they do not proliferate but remain metabolically active. Answer: X - S phase, Y