If the endosperm cells of an angiosperm seed are pentaloid , the such a seed may have been formed by which of the following parents ?

Options

A. Triploid female and diploid male.
B. Diploid male and tetraploid female.
C. Both parents are tertraploid.
D. Triploid male and diploid female.

Answer

To solve the question regarding the formation of a pentaploid (5n) endosperm in an angiosperm seed, we need to analyze the ploidy levels of the parent cells involved in the fertilization process. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding Endosperm Formation**:
- The endosperm in angiosperms is formed through a process called double fertilization. This involves the fusion of two sperm cells from the pollen grain with different nuclei in the female gametophyte.

2. **Ploidy of the Endosperm**:
- The endosperm is typically triploid (3n) because it is formed from one sperm cell (1n) fertilizing two polar nuclei (2n) in the female gametophyte.

3. **Identifying Ploidy for Pentaploid Endosperm**:
- In this case, we are looking for a pentaploid (5n) endosperm. This means that the endosperm must be formed from three nuclei: two from the female parent and one from the male parent.

4. **Determining the Female Parent's Ploidy**:
- If the endosperm is 5n and it is formed from two nuclei from the female parent, then the female parent must be tetraploid (4n). This is because:
- Two nuclei from the tetraploid female (2n from 4n) + one haploid sperm (1n from diploid male) = 5n.

5. **Determining the Male Parent's Ploidy**:
- The male parent must be diploid (2n) because the pollen grains (which are formed from the pollen mother cells) undergo meiosis to produce haploid pollen grains (1n).

6. **Conclusion**:
- Therefore, for the endosperm to be pentaploid, the female parent must be tetraploid (4n) and the male parent must be diploid (2n).

### Final Answer:
The seed may have been formed by a **tetraploid female parent and a diploid male parent**.