The core of the cilium/flagellum is composed of

Options

A. 2 pairs of microtubules
B. 9 pairs of microtubules
C. 11 pairs of microtubules
D. 10 pairs of microtubules

Answer

To answer the question "The core of the cilium/flagellum is composed of," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structures**:
- Cilia and flagella are hair-like structures that protrude from the surface of many eukaryotic cells. They are involved in movement and locomotion.

2. **Identify the Components**:
- The core structure of cilia and flagella is known as the axoneme. The axoneme is composed of microtubules.

3. **Microtubule Arrangement**:
- The axoneme typically has a specific arrangement of microtubules. In cilia and flagella, there are two central microtubules surrounded by nine pairs of outer microtubules. This arrangement is often referred to as the "9+2" structure.

4. **Count the Microtubules**:
- In total, there are 10 pairs of microtubules: 2 in the center and 9 pairs (18) in the outer ring. This gives a total of 20 microtubules in the axoneme.

5. **Select the Correct Option**:
- Based on the arrangement of microtubules, the correct answer to the question is that the core of the cilium/flagellum is composed of 10 pairs of microtubules.

### Final Answer:
The core of the cilium/flagellum is composed of **10 pairs of microtubules**.

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