Microtubules are absent in

Options

A. Mitochondria
B. Flagella
C. Spindle fibres
D. Centrioles

Answer

**Step-by-Step Solution:**

1. **Understanding Microtubules**: Microtubules are filamentous structures that are part of the cytoskeleton in eukaryotic cells. They play a crucial role in various cellular functions.

2. **Functions of Microtubules**:
- They are involved in the movement of cells.
- They contribute to the formation of the cytoskeleton.
- They are essential for spindle fiber formation during cell division.
- They are also involved in the formation of cilia and flagella.

3. **Location of Microtubules**: Microtubules are found in several cellular structures, including:
- Centrioles
- Basal bodies
- Cilia and flagella
- Spindle fibers

4. **Identifying the Absence of Microtubules**: The question asks where microtubules are absent. Among the options provided (myotocontia, flagella, sphincter), we need to identify which structure does not contain microtubules.

5. **Analyzing the Options**:
- **Myotocontia**: This term is not commonly used in biology, but if it refers to muscle-related structures, it may not contain microtubules.
- **Flagella**: Flagella are known to contain microtubules.
- **Sphincter**: Sphincters are muscle structures and do not typically have microtubules.

6. **Conclusion**: Based on the analysis, microtubules are absent in mitochondria, as they do not play a role in its structure or function. Therefore, the correct answer is **mitochondria**.

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