If male plan is hexaploid and female plant is tetraploid , the endoderm will be :

Options

A. 6n
B. 8n
C. 12n
D. 7n

Answer

To determine the ploidy level of the endosperm formed from a male hexaploid plant and a female tetraploid plant, we need to analyze the process of fertilization in plants, specifically focusing on the formation of the endosperm through double fertilization.

### Step-by-Step Solution:

1. **Identify the Ploidy Levels**:
- The male plant is hexaploid (6n).
- The female plant is tetraploid (4n).

2. **Formation of Male Gametes**:
- The male plant undergoes meiosis to produce pollen grains (male gametes).
- Since the male plant is hexaploid (6n), the pollen grains will be haploid (n) after meiosis.
- Therefore, the pollen grains will have a ploidy level of 3n (since 6n/2 = 3n).

3. **Formation of Female Gametes**:
- The female plant also undergoes meiosis to produce the female gametophyte.
- The female plant is tetraploid (4n), and after meiosis, the megaspores will be diploid (2n).
- The female gametophyte will consist of the egg cell (2n).

4. **Double Fertilization**:
- In plants, double fertilization occurs where one male gamete fertilizes the egg cell, and the other male gamete fuses with two polar nuclei.
- The first fertilization (syngamy) results in the formation of the zygote:
- Zygote = Male gamete (3n) + Egg cell (2n) = 3n + 2n = 5n.
- The second fertilization leads to the formation of the endosperm:
- Endosperm = Male gamete (3n) + Two polar nuclei (2n + 2n) = 3n + 4n = 7n.

5. **Conclusion**:
- Therefore, the endosperm formed will have a ploidy level of 7n.
- The correct answer is option D: 7n.