A plant root has 16 chromosomes , so

Options

A. (a) gamete has 16 chromosomes
B. (b) gamete has 8 chromosomes
C. (c) endosperm has 8 chromosomes
D. (d) endosperm has 16 chromosomes

Answer

To solve the problem, we need to determine the ploidy levels of the gametes and the endosperm based on the information given about the plant root having 16 chromosomes. Here’s a step-by-step breakdown:

### Step-by-Step Solution:

1. **Identify the Chromosome Number in the Plant Root:**
- The plant root has 16 chromosomes. This indicates that the plant is diploid (2n), meaning it has two sets of chromosomes, one from each parent.

2. **Determine the Ploidy Level of Gametes:**
- Gametes are produced through meiosis and are haploid (n). Since the plant root is diploid with 16 chromosomes, the gametes will have half the number of chromosomes.
- Calculation:
\[ \text{Number of chromosomes in gametes} = \frac{16}{2} = 8 \]
- Therefore, the gametes will have 8 chromosomes.

3. **Determine the Ploidy Level of Endosperm:**
- The endosperm is formed after fertilization and is typically triploid (3n). This means it has three sets of chromosomes.
- Calculation:
\[ \text{Number of chromosomes in endosperm} = 2 \times \text{(number of chromosomes in gametes)} = 2 \times 8 = 24 \]
- Therefore, the endosperm will have 24 chromosomes.

4. **Summarize the Findings:**
- The plant root (somatic cell) has 16 chromosomes (2n).
- The gametes have 8 chromosomes (n).
- The endosperm has 24 chromosomes (3n).

5. **Select the Correct Option:**
- Based on the findings:
- A: 16 chromosomes (incorrect for gametes and endosperm)
- B: 8 chromosomes (correct for gametes)
- C: 8 chromosomes (incorrect for endosperm)
- D: 16 chromosomes (incorrect for endosperm)
- The correct answer is option B.

### Final Answer:
The correct option is B: The gametes have 8 chromosomes.