Cell polarity is determined by
(a) Intermediate filaments
(b) Microtubules
(c) Protofilaments
(d) Centrioles

Options

A. Intermediate filaments
B. Microtubules
C. Protofilaments
D. Centrioles

Answer

To determine the correct answer to the question "Cell polarity is determined by," we need to analyze the options provided and understand the role of each component in relation to cell polarity.

### Step-by-Step Solution:

1. **Understanding Cell Polarity**:
- Cell polarity refers to the spatial differences in the shape, structure, and function of cells. It is crucial for various cellular processes, including cell signaling, movement, and division.

2. **Analyzing the Options**:
- **(a) Intermediate filaments**: These are part of the cytoskeleton and provide structural support to the cell. However, they are not primarily responsible for establishing cell polarity.
- **(b) Microtubules**: These are also part of the cytoskeleton and play a significant role in maintaining cell shape, intracellular transport, and cell division. They are crucial for establishing polarity in cells, particularly during processes like mitosis.
- **(c) Protofilaments**: These are linear polymers of tubulin that make up microtubules. While they are essential for the structure of microtubules, they do not directly determine cell polarity.
- **(d) Centrioles**: These are cylindrical structures involved in cell division and the formation of cilia and flagella. They help organize microtubules but are not directly responsible for establishing cell polarity.

3. **Identifying the Correct Answer**:
- Based on the analysis, microtubules (option b) are the primary components that contribute to cell polarity. They help in organizing the cellular structure and determining the orientation of the cell.

### Conclusion:
The correct answer is **(b) Microtubules**.

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