Total number of peripheral microtubules in flagella is (i) and in centrioles is (ii) .

Options

A. (i)-18, (ii)-27
B. (i)-27, (ii)-18
C. (i)-20, (ii)-27
D. (i)-27, (ii)-20

Answer

To determine the total number of peripheral microtubules in flagella and centrioles, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Flagella**:
- Flagella are lash-like appendages that extend from the cell body of certain cells, known as flagellates. They are primarily involved in locomotion.

2. **Identify the Composition of Flagella**:
- The structure of flagella includes microtubules, which are cylindrical structures made of protein subunits called alpha and beta tubulin.

3. **Determine the Number of Peripheral Microtubules in Flagella**:
- In flagella, there are typically **18 peripheral microtubules** arranged in a specific pattern.

4. **Understand the Structure of Centrioles**:
- Centrioles are cylindrical organelles found in animal cells, playing a crucial role in cell division and organization of the microtubules.

5. **Identify the Composition of Centrioles**:
- Similar to flagella, centrioles are also composed of microtubules.

6. **Determine the Number of Peripheral Microtubules in Centrioles**:
- In centrioles, there are typically **27 peripheral microtubules** arranged in a specific pattern.

7. **Summarize the Findings**:
- Therefore, the total number of peripheral microtubules in flagella is **18** (i) and in centrioles is **27** (ii).

### Final Answer:
- (i) 18
- (ii) 27

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