Identify the phase at which most organelles duplicates

Options

A. M-phase
B. `G_(1)` phase
C. `G_(0)` phase
D. `G_(2)` phase

Answer

To identify the phase at which most organelles duplicate, we can analyze each option provided in the question:

1. **Option A: M phase**
- The M phase, also known as the mitotic phase, is when cell division occurs. This includes karyokinesis (division of chromosomes) and cytokinesis (division of cytoplasm). However, during this phase, there is no duplication of organelles, DNA, or RNA. Therefore, this option is incorrect.

2. **Option B: G1 phase**
- The G1 phase, or gap 1 phase, is the first phase of interphase. During this phase, the cell grows and synthesizes proteins necessary for DNA replication. Importantly, most organelles duplicate during this phase. Thus, this option is correct.

3. **Option C: G0 phase**
- The G0 phase is known as the inactive or resting phase. In this phase, the cell has exited the cell cycle and lost its ability to divide. While metabolic activities may still occur, organelle duplication does not take place. Therefore, this option is also incorrect.

4. **Option D: G2 phase**
- The G2 phase is the second gap phase that occurs after DNA has been replicated. During this phase, the cell prepares for mitosis, synthesizing RNA and proteins. However, it is primarily a preparatory phase and does not involve significant organelle duplication. Thus, this option is incorrect as well.

Based on this analysis, the correct answer is **Option B: G1 phase**, where most organelles duplicate.