Endosperm nucleus is :

Options

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

Answer

To determine the ploidy level of the endosperm nucleus, we need to understand the process of double fertilization in angiosperms. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding Double Fertilization**:
- In angiosperms, the process of double fertilization occurs, which is a unique characteristic of these flowering plants.

2. **Release of Sperm Cells**:
- During double fertilization, the pollen tube penetrates the synergids and releases two sperm cells into the embryo sac.

3. **Formation of Zygote**:
- One of the sperm cells fuses with the egg cell, which is haploid (1n), resulting in the formation of a diploid zygote (2n).

4. **Formation of Endosperm**:
- The second sperm cell fuses with the two polar nuclei present in the embryo sac. The polar nuclei are also haploid (1n each), resulting in a triploid (3n) endosperm nucleus.

5. **Conclusion**:
- Therefore, the endosperm nucleus is triploid (3n) due to the fusion of one haploid sperm with two haploid polar nuclei.

6. **Final Answer**:
- The endosperm nucleus is triploid.