A cell that is entering the mitotic phase (M-phase) of cell cycle is :-

Options

A. always haploid or diploid and with duplicated chromosomes
B. either haploid or diploid and with duplicated chromosomes
C. either haploid or diploid and with duplicated or unduplicated chromosomes
D. always diploid and with unduplicated chromosomes

Answer

To determine the correct answer to the question about a cell entering the mitotic phase (M-phase) of the cell cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the M-phase**: The M-phase, or mitotic phase, is the part of the cell cycle where cell division occurs. This phase includes both mitosis (the division of the nucleus) and cytokinesis (the division of the cytoplasm).

2. **Identify the chromosome state**: Before a cell enters the M-phase, it must have duplicated its chromosomes during the S-phase (synthesis phase) of the cell cycle. This means that the chromosomes are in a duplicated state, consisting of two sister chromatids.

3. **Determine ploidy**: Cells can be either haploid (n) or diploid (2n).
- **Haploid cells** contain one set of chromosomes (e.g., gametes).
- **Diploid cells** contain two sets of chromosomes (e.g., somatic cells).

4. **Evaluate the options**:
- **Option A**: "Always haploid or diploid and with duplicated chromosomes." - This is incorrect because it states "always," which is misleading.
- **Option B**: "Either haploid or diploid with duplicated chromosomes." - This is correct as it accurately describes that the cell can be either haploid or diploid, but it must have duplicated chromosomes when entering M-phase.
- **Option C**: "Either haploid or diploid with duplicated or unduplicated chromosomes." - This is incorrect because cells entering M-phase must have duplicated chromosomes.
- **Option D**: "Always diploid and with unduplicated chromosomes." - This is incorrect as it incorrectly states that cells are always diploid and unduplicated.

5. **Select the correct answer**: Based on the evaluation, **Option B** is the correct answer. A cell that is entering the mitotic phase (M-phase) of the cell cycle can be either haploid or diploid, but it must have duplicated chromosomes.

### Final Answer:
A cell that is entering the mitotic phase (M-phase) of the cell cycle is **either haploid or diploid with duplicated chromosomes** (Option B).