Plastids contain

Options

A. Double membrane covering
B. DNA,RNA and ribosomes
C. Lamellae
D. All the above

Answer

### Step-by-Step Solution:

1. **Definition of Plastids**:
- Plastids are organelles found in plant cells and euglenoids. They play crucial roles in various functions such as photosynthesis, storage, and pigmentation.

2. **Types of Plastids**:
- There are different types of plastids, each serving specific functions:
- **Chloroplasts**: Responsible for photosynthesis.
- **Chromoplasts**: Provide color to the plant.
- **Leucoplasts**: Involved in storage functions.

3. **Characteristics of Plastids**:
- Plastids are characterized by having a double membrane structure, which means they have an outer and an inner membrane.
- They contain their own DNA, RNA, and ribosomes, which are essential for protein synthesis. The ribosomes found in plastids are of the prokaryotic type.

4. **Presence of Lamellae**:
- Lamellae are structures within plastids that help connect different parts of the plastid. They play a role in maintaining the organization of the plastid's internal structure.

5. **Conclusion**:
- Given the characteristics and components of plastids, we can conclude that they contain:
- Double membrane covering
- DNA, RNA, and ribosomes
- Lamellae
- Therefore, the correct answer to the question "Plastids contain" is **option 4: all of them**.