Consider the following four statements (I - IV) related to cell cycle, and select the correct option stating them as true [T] and false [F]. i. `G_1` phase is a metabolically active stage of the cell cycle. ii. Interphase is the phase of actual cell division. iii. The number of chromosomes doubles in S-phase. iv. The cells that do not divide further exit the `G_1` - phase to enter a quiescent stage.

Options

A. `{:(I,II,III,IV),(T,F,F,F):}`
B. `{:(I,II,III,IV),(F,T,T,T):}`
C. `{:(I,II,III,IV),(F,F,T,T):}`
D. `{:(I,II,III,IV),(T,F,F,T):}`

Answer

To solve the question, we need to evaluate each of the four statements related to the cell cycle and determine whether they are true (T) or false (F).

### Step-by-Step Solution:

1. **Evaluate Statement I: "G1 phase is a metabolically active stage of the cell cycle."**
- During the G1 phase, the cell is indeed metabolically active. It grows and prepares for DNA replication, although it does not replicate its DNA in this phase.
- **Conclusion:** This statement is **True (T)**.

2. **Evaluate Statement II: "Interphase is the phase of actual cell division."**
- The cell cycle consists of two main phases: interphase and mitosis (M phase). Interphase is the preparatory phase where the cell prepares for division, while mitosis is the actual phase of cell division.
- **Conclusion:** This statement is **False (F)**.

3. **Evaluate Statement III: "The number of chromosomes doubles in S-phase."**
- The S phase is where DNA replication occurs, and during this phase, the amount of DNA doubles, leading to the doubling of chromosomes. However, the number of chromosomes remains the same until the cell divides in mitosis.
- **Conclusion:** This statement is **False (F)**.

4. **Evaluate Statement IV: "The cells that do not divide further exit the G1 phase to enter a quiescent stage."**
- Cells that do not proceed to divide can exit the cell cycle from the G1 phase and enter a quiescent stage known as the G0 phase. This is a resting state where cells are metabolically active but do not divide.
- **Conclusion:** This statement is **True (T)**.

### Summary of Evaluations:
- Statement I: True (T)
- Statement II: False (F)
- Statement III: False (F)
- Statement IV: True (T)

### Final Answer:
The correct option stating the statements as true [T] and false [F] is:
- I: T
- II: F
- III: F
- IV: T