If the diploid number of a flowering plant is 18, what would be chromosome number in its endosperm?

Options

A. 18
B. 9
C. 27
D. 36

Explanation

To solve the question regarding the chromosome number in the endosperm of a flowering plant with a diploid number of 18, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Diploid Number (2n)**:
- The diploid number (2n) of the flowering plant is given as 18.

2. **Determine the Haploid Number (n)**:
- The haploid number (n) can be calculated by dividing the diploid number by 2.
- Formula: n = 2n / 2
- Calculation: n = 18 / 2 = 9

3. **Understand the Formation of Endosperm**:
- In flowering plants, the endosperm is formed from the fusion of a male gamete (which is haploid, n) with the secondary nucleus of the embryo sac (which is diploid, 2n).
- This fusion results in a triploid (3n) endosperm.

4. **Calculate the Chromosome Number in Endosperm (3n)**:
- Since we have determined that n = 9, we can calculate the chromosome number in the endosperm.
- Formula: 3n = 3 × n
- Calculation: 3n = 3 × 9 = 27

5. **Conclusion**:
- Therefore, the chromosome number in the endosperm of the flowering plant is 27.

### Final Answer:
The chromosome number in the endosperm is **27**.

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