Tick the correct statement

Options

A. Proximal and distal centrioles in the middle piece of sperm help anchor the flagellum
B. whereas proximal entrioleis non functional, distal centriole acts as basal body for the flagellum of sperm
C. The functions of proximal and distal centriolesare not known
D. Proximal centriole forms the spindle fibreas during cleavage an the distal centriole anchors the flagellum of sperm

Answer

To solve the question, we need to analyze each statement regarding the proximal and distal centrioles in the middle piece of sperm and determine which one is correct.

### Step-by-Step Solution:

1. **Understanding the Structure of Sperm:**
- The sperm consists of several parts: the head, midpiece, and tail (flagellum). The midpiece contains mitochondria and centrioles.

2. **Analyzing the First Statement:**
- The first statement claims that proximal and distal centrioles help anchor the flagellum.
- **Evaluation:** The distal centrioles do contribute to the formation of the flagellum, while the proximal centrioles are involved in microtubule formation. Therefore, this statement is not correct.

3. **Analyzing the Second Statement:**
- The second statement suggests that proximal centrioles are non-functional and distal centrioles act as a vessel body for the flagellum.
- **Evaluation:** This is misleading. While the distal centrioles do play a role in the flagellum's structure, the proximal centrioles are not entirely non-functional as they are involved in microtubule formation. So, this statement is also incorrect.

4. **Analyzing the Third Statement:**
- The third statement states that the function of proximal and distal centrioles is not known.
- **Evaluation:** This is incorrect as we do have knowledge about their functions, particularly in the context of sperm motility and structure.

5. **Analyzing the Fourth Statement:**
- The fourth statement claims that proximal centrioles form spindle fibers during cleavage and distal centrioles anchor the flagellum of the sperm.
- **Evaluation:** This statement is correct. Proximal centrioles do play a role in forming spindle fibers during cell division, and distal centrioles are indeed involved in anchoring the flagellum.

6. **Conclusion:**
- After evaluating all statements, the fourth statement is the correct one.

### Final Answer:
- The correct statement to tick is the fourth option.