In a flowering plant 2n = 24, the number of chromosomes in its endosperm will be :

Options

A. 18
B. 36
C. 20
D. 17

Answer

To solve the question regarding the number of chromosomes in the endosperm of a flowering plant with a diploid number of chromosomes (2n = 24), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Diploid Number**:
The question states that the diploid number (2n) of the flowering plant is 24. This means that the plant has 24 chromosomes in its somatic (body) cells.

2. **Calculate the Haploid Number**:
To find the haploid number (n), we divide the diploid number by 2:
\[ n = \frac{2n}{2} = \frac{24}{2} = 12 \]
So, the haploid number of chromosomes is 12.

3. **Understand the Formation of Endosperm**:
In flowering plants, the endosperm is formed through a process called triple fusion. During fertilization, one male gamete fuses with the egg cell (syngamy) to form the zygote, while the other male gamete fuses with two polar nuclei in the embryo sac to form the endosperm.

4. **Determine the Ploidy of Endosperm**:
The endosperm is formed by the fusion of three haploid nuclei (one from the male gamete and two from the polar nuclei). Therefore, the ploidy of the endosperm is triploid (3n).

5. **Calculate the Number of Chromosomes in the Endosperm**:
Since we have established that the haploid number (n) is 12, we can find the number of chromosomes in the triploid endosperm:
\[ \text{Number of chromosomes in endosperm} = 3n = 3 \times 12 = 36 \]

6. **Conclusion**:
The number of chromosomes in the endosperm of the flowering plant is 36.

### Final Answer:
**B. 36**

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