Which is not a plastid ?

Options

A. Chloroplast
B. Mitoplast
C. Chromoplast
D. Leucoplast

Answer

To determine which of the given options is not a plastid, we can analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Plastids**: Plastids are organelles found in the cells of plants and algae. They are involved in the synthesis and storage of food. The main types of plastids include chloroplasts, chromoplasts, and leucoplasts.

2. **Identifying the Options**:
- **Chloroplast**: This is a type of plastid that contains chlorophyll and is responsible for photosynthesis. It is a green plastid.
- **Chromoplast**: This is another type of plastid that contains various pigments, giving color to flowers and fruits. It is known as a colorful plastid.
- **Leucoplast**: This is a colorless plastid that is involved in the storage of starches, oils, and proteins. It is often found in non-photosynthetic tissues.
- **Metoplast**: This term refers to a structure that is described as a mitochondrion without a membrane. It is not recognized as a plastid.

3. **Conclusion**: Among the options provided, chloroplast, chromoplast, and leucoplast are all types of plastids. However, metoplast is not a plastid; it is a term used to describe a non-membrane-bound structure related to mitochondria.

4. **Final Answer**: The option that is not a plastid is **metoplast**.