Multiple choice

Mitotic cell cycle is divided into 4 phases G1, S, G2 and M. Considering a mitotic cycle time of 18 hours, the distribution of period of time for each of these phases will be

  1. G1-1 S-3 G2-5 M-9

  2. G1-9 S-1 G2-3 M-5

  3. G1-9 S-5 G2-3 M-1

  4. G1-3 S-5 G2-9 M-1
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In an 18-hour mitotic cycle, G1 is typically the longest phase as the cell grows and prepares for DNA synthesis. G1 occupies ~50% (9 hours), S phase ~28% (5 hours) for DNA replication, G2 ~17% (3 hours) for preparation, and M phase ~5% (1 hour) for mitosis itself. This distribution reflects the biological priority of growth preparation.

Keep practicing — related questions