Which one provides support to microvilli, membrane rufflings and pseudopodia

Options

A. Microfilaments
B. Desmin and vimentin filaments
C. Microtubules
D. E.R.

Answer

### Step-by-Step Solution

1. **Understanding the Question**: The question asks which structure provides support to microvilli, membrane rufflings, and pseudopodia. These structures are all types of cellular projections.

2. **Identifying the Options**: The options provided are:
- Microfilaments
- Desmins and vimentin filaments
- Microtubules
- Endoplasmic reticulum

3. **Analyzing Microvilli, Membrane Rufflings, and Pseudopodia**:
- **Microvilli**: These are small, finger-like projections found on the surface of certain cells, such as those in the small intestine, that increase surface area for absorption.
- **Membrane Rufflings**: These are dynamic, wave-like projections that help in cell motility and are often seen in cells that are moving or changing shape.
- **Pseudopodia**: These are temporary, foot-like extensions of the cell that help in movement and feeding, particularly in amoebas.

4. **Determining the Supporting Structure**:
- Microvilli, membrane rufflings, and pseudopodia are all supported by the **microfilaments** of the cytoskeleton. Microfilaments are primarily composed of actin protein and are crucial for maintaining cell shape and enabling movement.

5. **Evaluating Other Options**:
- **Desmins and Vimentin Filaments**: These are intermediate filaments that provide structural support but do not specifically support the projections mentioned.
- **Microtubules**: These are made of tubulin and provide structural support but are not directly involved in supporting microvilli or pseudopodia.
- **Endoplasmic Reticulum**: This is an organelle involved in protein and lipid synthesis, not in providing structural support to cellular projections.

6. **Conclusion**: Based on the analysis, the correct answer is **microfilaments**, as they provide the necessary support for microvilli, membrane rufflings, and pseudopodia.

### Final Answer
**Microfilaments**

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