Pinocytosis is an example of :

Options

A. facilitated transport
B. active transport
C. endocytosis
D. exocytosis

Explanation

**Step-by-Step Solution:**

1. **Understanding the Term Pinocytosis**: Pinocytosis is a cellular process where cells engulf liquid and small particles from their surrounding environment. This process is often referred to as "cell drinking."

2. **Identifying Types of Transport**: The question asks to classify pinocytosis among the given options: facilitated transport, active transport, endocytosis, or exocytosis.

3. **Defining Endocytosis**: Endocytosis is a general term for the process where cells take in substances from the outside environment. It includes various forms such as phagocytosis (cell eating) and pinocytosis (cell drinking).

4. **Classifying Pinocytosis**: Since pinocytosis involves the inward movement of liquid and small particles into the cell, it is classified as a type of endocytosis.

5. **Eliminating Other Options**:
- **Facilitated Transport**: This involves the movement of substances across a cell membrane via specific carrier proteins but does not involve engulfing particles.
- **Active Transport**: This process requires energy (ATP) to move substances against their concentration gradient, which is not the case in pinocytosis.
- **Exocytosis**: This is the process of expelling substances from the cell, which is the opposite of what pinocytosis does.

6. **Conclusion**: Therefore, pinocytosis is an example of endocytosis.

**Final Answer**: Pinocytosis is an example of endocytosis.

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