. What is the ploidy of primary endosperm nucleus (PEN) in angiosperm ?

Options

A. Haploid
B. Diploid
C. Triploid
D. Hexaploid

Answer

To determine the ploidy of the primary endosperm nucleus (PEN) in angiosperms, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Endosperm Formation**:
- The primary endosperm nucleus is formed during the fertilization process in angiosperms. It occurs when a pollen grain (which carries the male gamete) fuses with the two polar nuclei present in the embryo sac of the ovule.

2. **Identifying the Components Involved**:
- The pollen grain contributes one haploid (n) nucleus, while the two polar nuclei contribute two haploid (n) nuclei.

3. **Calculating the Total Ploidy**:
- Since the primary endosperm nucleus is formed by the fusion of one pollen nucleus and two polar nuclei, we can calculate the total ploidy:
- Ploidy from pollen grain = 1n
- Ploidy from two polar nuclei = 2n (1n + 1n)
- Total ploidy of the primary endosperm nucleus = 1n + 2n = 3n

4. **Conclusion**:
- Therefore, the ploidy of the primary endosperm nucleus (PEN) in angiosperms is triploid (3n).

### Final Answer:
The ploidy of the primary endosperm nucleus (PEN) in angiosperms is **triploid (3n)**.

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