Cristae are associated with:

Options

A. Endoplasmic reticulum
B. Mitochondria
C. Cytoplasm
D. Protoplasm

Answer

### Step-by-Step Solution

1. **Understanding Cristae**:
- Cristae are the folds found in the inner membrane of mitochondria. They play a crucial role in increasing the surface area for biochemical processes.

2. **Analyzing the Options**:
- **Option 1: Endoplasmic Reticulum**:
- The endoplasmic reticulum (ER) consists of rough and smooth types. The rough ER is involved in protein synthesis due to ribosomes on its surface, while the smooth ER is involved in lipid synthesis. Cristae are not associated with the ER, so this option is incorrect.

- **Option 2: Mitochondria**:
- Mitochondria are double-membraned organelles where cellular respiration occurs. The inner membrane has folds known as cristae, which increase the surface area for ATP production. This option is correct.

- **Option 3: Cytoplasm**:
- Cytoplasm is the semi-fluid substance inside the cell that contains various organelles but does not contain cristae. Therefore, this option is incorrect.

- **Option 4: Protoplasm**:
- Protoplasm refers to the living contents of a cell, including cytoplasm and the nucleus. It does not specifically relate to cristae, making this option incorrect.

3. **Conclusion**:
- The only option that correctly associates with cristae is **Mitochondria**.

### Final Answer
Cristae are associated with **Mitochondria**.

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