Select the incorrect statement with respect to centrioles.

Options

A. Cartwheel-like organization
B. They are made up of nine evenly spaced peripheral fibrils of tubulin
C. The cental part is non-proteinaceous and called the hub
D. They form the basal body of cilia or flagella.

Answer

To solve the question regarding the incorrect statement about centrioles, let's break down the information step by step:

### Step 1: Understand the Structure of Centrioles
Centrioles are cylindrical structures found in the centrosome. Each centrosome contains two centrioles that are arranged perpendicularly to each other.

**Hint:** Remember that centrioles are part of the centrosome and are arranged in pairs.

### Step 2: Identify the Organization of Centrioles
Each centriole has a unique structure that resembles a "cartwheel," which is indicative of its organization.

**Hint:** Think about the visual representation of a cartwheel to recall the structure of centrioles.

### Step 3: Composition of Centrioles
Centrioles are composed of nine evenly spaced peripheral fibrils made of tubulin protein. This is a key feature of their structure.

**Hint:** Focus on the number of fibrils and the material they are made from (tubulin).

### Step 4: Central Part of Centrioles
The central part of a centriole is known as the "hub," and it is proteinaceous, meaning it is made up of proteins. This is crucial to note because it contradicts the incorrect statement.

**Hint:** Remember that the central hub is proteinaceous, which is essential for its function.

### Step 5: Function of Centrioles
Centrioles play a significant role in forming basal bodies for cilia and flagella, as well as in the formation of astral spindle poles during cell division.

**Hint:** Link the function of centrioles to their role in cellular structures like cilia and flagella.

### Conclusion: Identify the Incorrect Statement
Now, let's analyze the options given in the question:
1. Cartwheel-like organization: **Correct**
2. Made up of 9 evenly spaced peripheral fibrils of tubulin: **Correct**
3. The central part is non-proteinaceous and called the hub: **Incorrect** (it is proteinaceous)
4. They form the basal body of cilia or flagella: **Correct**

Based on this analysis, the incorrect statement is option 3: "The central part is non-proteinaceous and called the hub."

**Final Answer:** The incorrect statement is option 3.