If diploid chromosome number in a flowering plant is 12, then which one of the following will have only 6 chromosomes

Options

A. Endosperm
B. Leaf cells
C. Cotyledons
D. Synergids

Answer

To solve the question, "If diploid chromosome number in a flowering plant is 12, then which one of the following will have only 6 chromosomes?", we can follow these steps:

### Step 1: Understand the Diploid and Haploid Numbers
- The diploid (2n) chromosome number is given as 12. This means that in the somatic cells of the plant, there are 12 chromosomes.
- The haploid (n) chromosome number can be calculated by dividing the diploid number by 2:
\[ n = \frac{2n}{2} = \frac{12}{2} = 6 \]

**Hint:** Remember that haploid cells have half the number of chromosomes compared to diploid cells.

### Step 2: Analyze the Options
We need to determine which of the given options corresponds to a haploid cell with 6 chromosomes.

1. **Endosperm**:
- The endosperm is formed by the fusion of one male gamete (n) and two polar nuclei (which are diploid). Thus, the endosperm is triploid (3n).
- Since 3n = 12, it has 18 chromosomes.
- **Conclusion**: Not the answer.

2. **Leaf Cells**:
- Leaf cells are somatic cells, which are diploid (2n).
- Since 2n = 12, leaf cells have 12 chromosomes.
- **Conclusion**: Not the answer.

3. **Cotyledons**:
- Cotyledons are also part of the embryo and are diploid (2n).
- Since 2n = 12, cotyledons have 12 chromosomes.
- **Conclusion**: Not the answer.

4. **Synergids**:
- Synergids are part of the female gametophyte and develop from a haploid megaspore.
- They are haploid (n), and since n = 6, synergids have 6 chromosomes.
- **Conclusion**: This is the correct answer.

### Step 3: Final Answer
After analyzing all the options, the only structure that has 6 chromosomes is **synergids**.

**Final Answer:** Synergids

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