In angiosperms, ……………nuclei participate in fertilization.

Options

A. 2
B. 4
C. 5
D. 7

Answer

To solve the question regarding how many nuclei participate in fertilization in angiosperms, we can break it down step by step:

### Step-by-Step Solution:

1. **Understanding Angiosperms**:
- Angiosperms are flowering plants that undergo a unique process of fertilization known as double fertilization.

2. **Double Fertilization**:
- In double fertilization, two male gametes (sperm cells) from the pollen grain are involved in the fertilization process.

3. **First Fusion (Syngamy)**:
- One male gamete fuses with the female gamete (egg cell) to form a zygote. This zygote is diploid (2n) because it contains one set of chromosomes from the male and one set from the female.

4. **Second Fusion (Triple Fusion)**:
- The second male gamete travels down the pollen tube and fuses with the two polar nuclei present in the embryo sac. This fusion results in the formation of a primary endosperm nucleus, which is triploid (3n) because it contains three sets of chromosomes (one from the male gamete and two from the polar nuclei).

5. **Total Nuclei Count**:
- In total, during the fertilization process:
- The zygote contributes 2 nuclei (from the egg and the male gamete).
- The primary endosperm nucleus contributes 3 nuclei (from the two polar nuclei and the male gamete).
- Therefore, the total number of nuclei participating in fertilization is:
- 2 (from the zygote) + 3 (from the primary endosperm nucleus) = 5 nuclei.

6. **Conclusion**:
- Thus, the correct answer to the question is that **5 nuclei participate in fertilization in angiosperms**.

### Final Answer:
**5 nuclei participate in fertilization in angiosperms.**