The ploidy levels of the cells of the nucellus, MMC, the functional megaspore and female gametophyte-

Options

A. 2N,N,2N,N
B. N,N,2N,N
C. 2N,2N,N,N
D. N,2N,2N,N

Answer

To determine the ploidy levels of the cells of the nucellus, megaspore mother cell (MMC), functional megaspore, and female gametophyte, we can analyze each component step by step.

### Step-by-Step Solution:

1. **Understanding Nucellus**:
- The nucellus is a tissue found within the ovule of flowering plants. It is part of the ovule and provides nourishment to the developing embryo sac.
- **Ploidy Level**: The nucellus is diploid (2n) because it arises from the sporophyte generation of the plant.

2. **Megaspore Mother Cell (MMC)**:
- The MMC is a diploid cell that undergoes meiosis to produce megaspores. It is also known as the megasporocyte.
- **Ploidy Level**: The MMC is diploid (2n).

3. **Functional Megaspore**:
- The functional megaspore is produced from the meiotic division of the MMC. Typically, one of the four megaspores formed through meiosis will survive and develop into the female gametophyte.
- **Ploidy Level**: The functional megaspore is haploid (n) as a result of meiosis.

4. **Female Gametophyte**:
- The female gametophyte, also known as the embryo sac, develops from the functional megaspore. It contains the egg cell and other cells necessary for fertilization.
- **Ploidy Level**: The female gametophyte is also haploid (n) since it develops from the haploid functional megaspore.

### Summary of Ploidy Levels:
- Nucellus: 2n (diploid)
- MMC: 2n (diploid)
- Functional Megaspore: n (haploid)
- Female Gametophyte: n (haploid)

### Final Answer:
The correct ploidy levels are: 2n (nucellus), 2n (MMC), n (functional megaspore), and n (female gametophyte).