The endosperm nucleus in angiosperms is

Options

A. haploid
B. diploid
C. triploid
D. tetraploid

Answer

To determine the nature of the endosperm nucleus in angiosperms, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Endosperm**:
- The endosperm is a tissue found inside the seeds of most flowering plants (angiosperms). It serves as a food reserve for the developing embryo.

2. **Double Fertilization**:
- Angiosperms exhibit a unique process called double fertilization. This involves the fusion of two sperm cells from the pollen with different structures in the ovule.

3. **Formation of the Zygote and Endosperm**:
- One sperm cell fuses with the egg cell to form the zygote (which will develop into the embryo).
- The other sperm cell fuses with the two polar nuclei located in the central cell of the ovule. This fusion results in the formation of the endosperm.

4. **Chromosome Count**:
- The zygote formed is diploid (2n) because it contains two sets of chromosomes (one from each parent).
- The endosperm, however, is triploid (3n) because it is formed from the fusion of one sperm cell (1n) with two polar nuclei (2n).

5. **Conclusion**:
- Therefore, the endosperm nucleus in angiosperms is triploid.

### Final Answer:
The endosperm nucleus in angiosperms is **triploid (3n)**.

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