In each segment of cockroach, the exoskeleton has hardened plates called :

Options

A. Ossicles
B. Keratin
C. Sclerites
D. None of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Exoskeleton of Cockroach**: The cockroach has a rigid outer covering known as the exoskeleton. This exoskeleton is made primarily of a substance called chitin, which provides protection and support to the body.

2. **Identifying the Components of the Exoskeleton**: The exoskeleton is not uniform; it consists of various components, including hardened plates. These plates are crucial for the structure and function of the cockroach's body.

3. **Defining the Hardened Plates**: In each segment of the cockroach's body, there are specific hardened plates that serve as structural elements. These plates are essential for the cockroach's movement and protection.

4. **Naming the Hardened Plates**: The hardened plates found in each segment of the cockroach are specifically referred to as "sclerites." Each segment has one sclerite, which is a single unit of the exoskeleton.

5. **Connection of Sclerites**: The sclerites are connected to each other by a flexible membrane known as the arthrodial membrane. This allows for movement between the segments while maintaining the overall structure of the exoskeleton.

6. **Conclusion**: Therefore, the answer to the question is that in each segment of a cockroach, the exoskeleton has hardened plates called "sclerites."

**Final Answer**: Sclerites.

---