In an angiosperm, a female plant having 2n = 24 is crossed with a male plant having 2n = 12. What will be the chromosome number of endosperm

Options

A. 12
B. 18
C. 24
D. 30

Answer

To determine the chromosome number of the endosperm in the given cross between a female angiosperm plant and a male angiosperm plant, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Chromosome Numbers:**
- The female plant has a diploid chromosome number (2n) of 24.
- The male plant has a diploid chromosome number (2n) of 12.

2. **Determine the Haploid Numbers:**
- The haploid (n) number for the female plant can be calculated as:
\[ n = \frac{2n}{2} = \frac{24}{2} = 12 \]
- The haploid (n) number for the male plant can be calculated as:
\[ n = \frac{2n}{2} = \frac{12}{2} = 6 \]

3. **Understand the Formation of Endosperm:**
- The endosperm in angiosperms is formed through a process known as triple fusion.
- During this process, one male gamete (haploid) fuses with the diploid central cell (which consists of two polar nuclei).

4. **Calculate the Chromosome Number of the Endosperm:**
- The central cell (diploid) has a chromosome number of 24 (2n = 24).
- The male gamete contributes a haploid number of 6 (n = 6).
- The endosperm is formed by the fusion of these two, resulting in:
\[ 2n + n = 24 + 6 = 30 \]
- Therefore, the chromosome number of the endosperm is 3n = 30.

5. **Conclusion:**
- The chromosome number of the endosperm is 30.

### Final Answer:
The chromosome number of the endosperm is **30**.