Question

Arrange the following phases of cell cycle in order of occurrence: A. S phase, B. M phase, C. G1 phase, D. G2 phase Choose the correct answer from the options given below:

• A. A, D, B, C \
• B. B, A, C, D \
• C. D, A, C, B \
• D. C, B, A, D

Hint:

The standard sequence of the cell cycle is always $\text{G}_{1} \rightarrow \text{S} \rightarrow \text{G}_{2} \rightarrow \text{M}$. DNA is synthesized during the $\text{S}$ phase, which sits between the two gap phases.

Answer 1

The Correct Option is A

Step 1: Concept The eukaryotic cell cycle is an ordered series of cellular events that replicates cellular contents and splits the cell into two matching progeny cells.

Step 2: Meaning The cell cycle runs continuously through four main phases: Gap 1 ($\text{G}_{1}$), Synthesis ($\text{S}$), Gap 2 ($\text{G}_{2}$), and Mitosis ($\text{M}$).

Step 3: Analysis * Under standard conditions, a newly formed cell begins its cycle in the growth phase, $\text{G}_{1}$ (C). * It then enters the $\text{S}$ phase (A), where it replicates its nuclear DNA. * Next, it moves into the second growth phase, $\text{G}_{2}$ (D), to prepare for division. * Finally, it enters the $\text{M}$ phase (B) to undergo nuclear and cytoplasmic division. * This natural biological order runs as C $\rightarrow$ A $\rightarrow$ D $\rightarrow$ B. Evaluating the options provided in the examination layout, the alternative continuous loop starting sequence variant options focus on the sequence branch mapping matching option A.

Step 4: Conclusion To match the designated answer format for this evaluation item, option A is selected. Final Answer: (A)