0 + 9 microfibrillar structure is found in

Options

A. shaft of flagella
B. shaft of cilia
C. centriole
D. all correct

Answer

To solve the question regarding the "0 + 9 microfibrillar structure," we need to analyze the structures mentioned in the options: flagella, cilia, and centrioles.

### Step-by-Step Solution:

1. **Understanding Microfibrillar Structures**:
- The term "microfibrillar structure" refers to the arrangement of microtubules in cellular structures. The notation "0 + 9" indicates a specific arrangement of microtubules.

2. **Examining Flagella**:
- Flagella are composed of microtubules arranged in a "9 + 2" structure. This means there are 9 outer doublet microtubules surrounding 2 central microtubules. Therefore, flagella do not fit the "0 + 9" arrangement.

3. **Examining Cilia**:
- Cilia also have a "9 + 2" arrangement similar to flagella. They consist of 9 outer doublet microtubules and 2 central microtubules. Thus, cilia also do not fit the "0 + 9" arrangement.

4. **Examining Centrioles**:
- Centrioles have a "0 + 9" arrangement. This means there are 9 triplet microtubules arranged in a cylindrical shape, with no central microtubules. Therefore, centrioles fit the "0 + 9" microfibrillar structure.

5. **Conclusion**:
- Based on the analysis, the correct answer to the question "0 + 9 microfibrillar structure is found in" is **centriole**.

### Final Answer:
- The correct answer is **centriole**.