Which one is diploid

Options

A. (a) Synergids
B. (b) Secondary nucleus
C. (c) Egg
D. (d) Antipodals

Answer

To determine which component is diploid, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Ploidy**:
- Ploidy refers to the number of sets of chromosomes in a cell. Diploid cells have two sets (2n), while haploid cells have one set (n).

2. **Identify the Components of Embryo Sac**:
- The embryo sac is a structure found in the female gametophyte of flowering plants (angiosperms) and contains several types of cells.

3. **Recognize the Megaspore Mother Cell**:
- The megaspore mother cell is diploid (2n) and undergoes meiosis to produce four haploid (n) megaspores.

4. **Mitosis of Megaspores**:
- Out of the four haploid megaspores, typically only one survives and undergoes mitosis to form the embryo sac, which is haploid.

5. **Analyze the Components of the Embryo Sac**:
- The embryo sac contains several types of cells:
- **Synergids**: Haploid (n)
- **Antipodal Cells**: Haploid (n)
- **Egg Cell**: Haploid (n)
- **Polar Nuclei**: These are formed by the fusion of two haploid nuclei and are diploid (2n).

6. **Identify the Diploid Component**:
- Among the components listed, the polar nuclei (which fuse to form the secondary nucleus) are diploid (2n).

7. **Select the Correct Answer**:
- Based on the analysis, the correct answer to the question "Which one is diploid?" is the polar nuclei.

### Final Answer:
- The diploid component is the **polar nuclei**.

---