Question

Arrange the following cell cycle stages in the correct order of their occurrence:
A. S phase
B. M phase
C. G1 phase
D. G2 phase

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

Hint:

A simple mnemonic to remember the order of the cell cycle is "Go Sally Go! Make Children!". \textbf{G}o → \textbf{G1} \textbf{S}ally → \textbf{S} phase \textbf{G}o → \textbf{G2} \textbf{M}ake \textbf{C}hildren → \textbf{M} phase (\textbf{C}ytokinesis)

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The cell cycle is the ordered series of events that leads to cell division and the production of two daughter cells. It is broadly divided into two main periods: Interphase, where the cell grows and replicates its DNA, and the Mitotic (M) phase, where the cell divides.

Step 2: Detailed Explanation:
Interphase is further subdivided into three distinct phases that occur in a specific sequence:
1. G1 phase (Gap 1): This is the first phase after a cell has just divided. During G1, the cell grows in size and synthesizes proteins and mRNA necessary for DNA synthesis. This corresponds to letter C.
2. S phase (Synthesis): Following G1, the cell enters the S phase. The primary event in this phase is the replication of the cell's DNA. This corresponds to letter A.
3. G2 phase (Gap 2): After DNA replication is complete, the cell enters the G2 phase. In this phase, the cell continues to grow and synthesizes proteins required for mitosis. It's a period of preparation for cell division. This corresponds to letter D.
After Interphase (G1, S, and G2) is complete, the cell enters the final phase of the cycle:
4. M phase (Mitosis): This phase involves the separation of the duplicated chromosomes (mitosis) and the division of the cytoplasm (cytokinesis) to form two identical daughter cells. This corresponds to letter B.

Step 3: Final Answer:
The correct sequence of the cell cycle stages is G1 \(\rightarrow\) S \(\rightarrow\) G2 \(\rightarrow\) M.
Using the given letters, the order is C \(\rightarrow\) A \(\rightarrow\) D \(\rightarrow\) B.
This sequence matches option (C).