Cytoskeleton is made up of

Options

A. cellulosic microfibrils
B. proteinaceous filaments
C. calcium carbonate granules
D. callose deposits

Answer

**Step-by-Step Solution:**

1. **Understanding Cytoskeleton**: The cytoskeleton is a network of fibers that provides structural support to the cell, much like a skeleton does for the body. It helps maintain the shape of the cell and is involved in various cellular functions.

2. **Components of Cytoskeleton**: The cytoskeleton is primarily made up of two types of proteinaceous structures:
- **Microfilaments**: These are thin, thread-like structures composed of actin proteins. They play a crucial role in maintaining the cell's shape and facilitating movement.
- **Microtubules**: These are hollow, tube-like structures made of tubulin proteins. They provide rigidity and shape to the cell and are involved in intracellular transport and cell division.

3. **Evaluating Options**:
- **Option 1**: Cellulosic microfibrils - Incorrect, as cellulose is a carbohydrate and not a proteinaceous component.
- **Option 2**: Proteinaceous filaments - Correct, as both microfilaments and microtubules are made of proteins.
- **Option 3**: Calcium carbonate granules - Incorrect, as these are hard granules and not part of the cytoskeleton.
- **Option 4**: Callose deposits - Incorrect, as callose is a polysaccharide and not a protein.

4. **Conclusion**: The correct answer is that the cytoskeleton is made up of proteinaceous filaments, specifically microfilaments and microtubules.

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