Choose the number of diploid structures in the list given below :- Pollen grains, nucellus, perisperm, endosperm, embryosac, megaspore

Options

A. Two
B. Three
C. Four
D. Five

Answer

To determine the number of diploid structures from the given list, we need to analyze each structure based on its ploidy level.

1. **Pollen Grains**: These are the male gametophytes and are typically haploid (n), as they develop from microspores. Therefore, they are not diploid.

2. **Nucellus**: This is the tissue that surrounds the ovule and is diploid (2n). It is part of the ovule and contributes to the formation of the seed.

3. **Perisperm**: This is a nutritive tissue that develops from the nucellus and is also diploid (2n). It is formed by mitosis of the nucellus.

4. **Endosperm**: This is a triploid (3n) tissue that provides nutrition to the developing embryo. It is formed by the fusion of two polar nuclei with a sperm nucleus during fertilization.

5. **Embryo Sac**: The embryo sac is the female gametophyte and is haploid (n), containing the egg cell and other nuclei.

6. **Megaspore**: This is a diploid structure (2n) that gives rise to the embryo sac through meiosis.

Now, let's summarize the ploidy levels:

- Pollen Grains: Haploid (n)
- Nucellus: Diploid (2n)
- Perisperm: Diploid (2n)
- Endosperm: Triploid (3n)
- Embryo Sac: Haploid (n)
- Megaspore: Diploid (2n)

**Counting the Diploid Structures**:
The diploid structures are:
- Nucellus (2n)
- Perisperm (2n)
- Megaspore (2n)

Thus, there are **3 diploid structures** in total.

### Final Answer:
**The number of diploid structures is 3.**