Each centriole has a cart wheel organisation having a whorl of tubulin fibrils at periphery. These peripheral fibrils are composed of how many microtubules?

Options

A. 11
B. 18
C. 9
D. 27

Answer

To solve the question regarding the composition of microtubules in the peripheral fibrils of each centriole, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of Centrioles**:
- Each centriole is made up of a specific arrangement of microtubules. They are organized in a cylindrical shape.

2. **Identifying the Arrangement**:
- The arrangement is often described as a "cartwheel" structure. This means that there are multiple microtubules arranged around a central axis.

3. **Counting the Microtubules**:
- Each centriole has a total of **nine** peripheral fibrils. These fibrils are actually triplets of microtubules.

4. **Calculating the Total Microtubules**:
- Since there are **nine** triplets of microtubules at the periphery, we can calculate the total number of microtubules by multiplying the number of triplets by the number of microtubules in each triplet:
\[ 9 \text{ triplets} \times 3 \text{ microtubules per triplet} = 27 \text{ microtubules} \]

5. **Conclusion**:
- Therefore, the peripheral fibrils of each centriole are composed of **27 microtubules**.

### Final Answer:
- Each centriole has a cartwheel organization with peripheral fibrils composed of **27 microtubules**.

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