A certain type of grass has a diploid chromosome number of 8. A similar species of grass has a diploid chromosome number of 10. Interspecific hybridisation between the two species results in sterile hybrids that can, nonetheles, reproduce vegetatively. The diploid chromosome number of these hybrids would be

Options

A. 9
B. 16
C. 18
D. 20

Explanation

To solve the problem, we need to determine the diploid chromosome number of the hybrids resulting from interspecific hybridization between two species of grass. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Identify the Diploid Chromosome Numbers**:
- Grass A has a diploid chromosome number of 8.
- Grass B has a diploid chromosome number of 10.

2. **Determine the Haploid Chromosome Numbers**:
- The haploid chromosome number (n) for Grass A can be calculated as:
\[ n = \frac{\text{Diploid number}}{2} = \frac{8}{2} = 4 \]
- The haploid chromosome number (n) for Grass B can be calculated as:
\[ n = \frac{\text{Diploid number}}{2} = \frac{10}{2} = 5 \]

3. **Calculate the Diploid Chromosome Number of the Hybrid**:
- When these two species undergo interspecific hybridization, the resulting hybrid will have a diploid chromosome number that is the sum of the haploid numbers from both parents:
\[ \text{Diploid number of hybrid} = n_A + n_B = 4 + 5 = 9 \]

4. **Conclusion**:
- Therefore, the diploid chromosome number of the resulting hybrids is **9**.

### Final Answer:
The diploid chromosome number of these hybrids would be **9**.

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