What would be the number of chromosomes of the aleurone cells of a plant with 42 chromosomes in its root tip cells?

Options

A. 42
B. 63
C. 84
D. 21

Answer

To determine the number of chromosomes in the aleurone cells of a plant with 42 chromosomes in its root tip cells, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the chromosome number in root tip cells**:
- The problem states that the root tip cells have 42 chromosomes. Root tip cells are typically diploid (2n), meaning they contain two sets of chromosomes.

2. **Determine the diploid number (2n)**:
- Since the root tip cells are diploid (2n = 42), we can find the haploid number (n) by dividing the diploid number by 2.
- Calculation:
\[ n = \frac{2n}{2} = \frac{42}{2} = 21 \]

3. **Understand the chromosome number in aleurone cells**:
- Aleurone cells are part of the endosperm and are typically triploid (3n) due to the process of double fertilization in flowering plants.

4. **Calculate the triploid number (3n)**:
- To find the number of chromosomes in the aleurone cells, we multiply the haploid number by 3.
- Calculation:
\[ 3n = 3 \times n = 3 \times 21 = 63 \]

5. **Conclusion**:
- Therefore, the number of chromosomes in the aleurone cells is 63.

### Final Answer:
The number of chromosomes in the aleurone cells is **63**.

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