In plant A, 2n = 12 and in plant B, 2n =. 16. Then the ploidy number of cross breeding plant is

Options

A. 7
B. 21
C. 14
D. 28

Answer

To determine the ploidy number of the crossbreeding plant between plant A and plant B, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the diploid number (2n) for both plants:**
- For plant A, the diploid number (2n) is given as 12.
- For plant B, the diploid number (2n) is given as 16.

2. **Calculate the haploid number (n) for both plants:**
- The haploid number (n) is half of the diploid number (2n).
- For plant A:
\[ n_A = \frac{2n_A}{2} = \frac{12}{2} = 6 \]
- For plant B:
\[ n_B = \frac{2n_B}{2} = \frac{16}{2} = 8 \]

3. **Determine the total number of chromosomes in the hybrid (crossbreeding plant):**
- When plant A and plant B crossbreed, the total number of chromosomes in the hybrid will be the sum of the haploid numbers from both plants:
\[ n_{hybrid} = n_A + n_B = 6 + 8 = 14 \]

4. **Calculate the diploid number (2n) for the hybrid:**
- Since the hybrid has a haploid number of 14, we can find the diploid number (2n) by doubling the haploid number:
\[ 2n_{hybrid} = 2 \times n_{hybrid} = 2 \times 14 = 28 \]

5. **Conclusion:**
- The ploidy number of the crossbreeding plant is 14 (haploid) or 28 (diploid).

### Final Answer:
The ploidy number of the crossbreeding plant is **14** (haploid) or **28** (diploid).

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