Question

Match List-I with List-II
List-I (Phase of the Cell Cycle) vs List-II (Time Duration)
(A) M Phase - (I) $\sim$ 10 hours
(B) G1 Phase - (II) $\sim$ 1 hour
(C) S Phase - (III) 2 to 6 hours
(D) G2 Phase - (IV) 6 to 8 hours
Choose the correct answer from the options given below:

• (A) - (III), (B) - (I), (C) - (II), (D) - (IV)
• (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
• (A) - (I), (B) - (III), (C) - (IV), (D) - (II)
• (A) - (IV), (B) - (I), (C) - (II), (D) - (III)

Hint:

To easily solve cell cycle duration questions:
M phase is always the shortest ($\approx 1\text{ hour}$), and $\text{G}_1$ is generally the longest ($\approx 10\text{ hours}$ in a 24-hr cycle).
Identifying these two extremes allows you to quickly eliminate incorrect options.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The eukaryotic cell cycle is divided into Interphase (consisting of $\text{G}_1$, $\text{S}$, and $\text{G}_2$ phases) and the Mitotic ($\text{M}$) phase.
For a typical rapidly proliferating human cell with a total generation time of approximately $24\text{ hours}$, each phase has a characteristic average duration.
Detailed Explanation:
Let us analyze the standard duration of each phase in a typical mammalian cell cycle:
- (A) M Phase (Mitosis and Cytokinesis): This is the shortest phase of the cell cycle, where the cell actively divides.
It typically takes only about 1 hour (representing approx. $5\%$ of the total cell cycle duration).
This matches with (II).
- (B) G1 Phase (Gap 1): This is the period of cell growth and preparation for DNA replication.
It is usually the longest and most variable phase of the cycle, typically lasting about 10 hours.
This matches with (I).
- (C) S Phase (Synthesis): This is the period during which the nuclear DNA is completely replicated.
It typically takes about 6 to 8 hours to ensure high-fidelity duplication of the genome.
This matches with (IV).
- (D) G2 Phase (Gap 2): This is the final preparation phase for mitosis.
It typically lasts about 2 to 6 hours.
This matches with (III).
Combining these matches, we get: (A) - (II), (B) - (I), (C) - (IV), (D) - (III).

Step 2: Final Answer:
The correct matching sequence corresponds to option (B).