Question

Select the phases which are included in the 'Interphase'.
A. S phase
B. M phase
C. G₁ phase
D. G₂ phase
Choose the correct answer from the options given below:

• A. A, B and D only
• B. B and D only
• C. A, C and D only
• D. B, C and D only

Hint:

Think of the cell cycle as a life story. \textbf{Interphase} is the long period of "living, growing, and preparing" (G₁, S, G₂). \textbf{M phase} is the short, dramatic event of "reproduction" or division. M phase is never part of Interphase.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The question asks to identify the specific phases that constitute the 'Interphase' part of the eukaryotic cell cycle. The cell cycle is the series of events that take place in a cell leading to its division and duplication.
Step 2: Detailed Explanation:
The eukaryotic cell cycle is broadly divided into two main stages:

Interphase: This is the longest phase of the cell cycle. It is the period of cell growth and DNA replication in preparation for cell division. Interphase is further subdivided into three distinct phases:

G₁ phase (Gap 1): (C) The cell grows in size and synthesizes mRNA and proteins required for DNA synthesis.
S phase (Synthesis): (A) The cell replicates its DNA. At the end of this phase, each chromosome consists of two sister chromatids.
G₂ phase (Gap 2): (D) The cell continues to grow and produces proteins and organelles needed for mitosis.

M phase (Mitotic phase): (B) This is the phase of actual cell division. It consists of mitosis (nuclear division) and cytokinesis (cytoplasmic division).
Therefore, Interphase includes the G₁, S, and G₂ phases. The M phase is the separate, subsequent stage of division.
Step 3: Final Answer:
The phases included in Interphase are S phase (A), G₁ phase (C), and G₂ phase (D). The correct option is A, C and D only.