Double membrane envelope is found around
1. Nucleus 2. Plastids 3. Mitochondria 4. ER

Options

A. I and II
B. II and III
C. III and IV
D. I,II and III

Answer

To solve the question regarding which structures have a double membrane envelope, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Double Membrane Structures**:
- A double membrane structure consists of two lipid bilayers surrounding an organelle or a nucleus.

2. **Analyzing Each Option**:
- **Option 1: Nucleus**:
- The nucleus is surrounded by a nuclear envelope, which consists of two membranes: an outer membrane and an inner membrane.
- **Conclusion**: The nucleus has a double membrane envelope.

- **Option 2: Plastids**:
- Plastids, such as chloroplasts, are also surrounded by a double membrane. They have an outer and an inner membrane.
- **Conclusion**: Plastids have a double membrane envelope.

- **Option 3: Mitochondria**:
- Mitochondria are known for their double membrane structure, consisting of an outer membrane and an inner membrane.
- **Conclusion**: Mitochondria have a double membrane envelope.

- **Option 4: Endoplasmic Reticulum (ER)**:
- The endoplasmic reticulum is not surrounded by a double membrane; it consists of a single membrane that forms a network of tubules and sacs.
- **Conclusion**: The endoplasmic reticulum does not have a double membrane envelope.

3. **Final Evaluation**:
- From the analysis, we find that:
- Nucleus: Double membrane (Correct)
- Plastids: Double membrane (Correct)
- Mitochondria: Double membrane (Correct)
- Endoplasmic Reticulum: Single membrane (Incorrect)
- Therefore, the correct answer is that the double membrane envelope is found around the **Nucleus, Plastids, and Mitochondria**.

### Final Answer:
The correct options are **1 (Nucleus), 2 (Plastids), and 3 (Mitochondria)**.

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