Sclerites are joined to each other by thin and flexible membrane called 

Options

A. arthrodial membrane
B. epicranial structures
C. Basement membrane
D. none

Answer

To solve the question regarding what the thin and flexible membrane that joins sclerites together is called, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the term "sclerites":**
- Sclerites are hard, plate-like structures that form part of the exoskeleton of certain arthropods, such as cockroaches. They provide protection and support to the body.

2. **Identify the types of sclerites:**
- In cockroaches, sclerites are categorized into three types:
- **Tergum:** The dorsal (upper) sclerites.
- **Sternum:** The ventral (lower) sclerites.
- **Pleurites:** The lateral (side) sclerites.

3. **Determine how sclerites are connected:**
- Sclerites are not rigidly fixed to each other; instead, they are joined by a flexible membrane that allows for movement.

4. **Identify the correct term for the membrane:**
- The thin and flexible membrane that connects the sclerites is known as the **arthrodial membrane**.

5. **Evaluate the options provided:**
- **Option 1:** Arthrodial membrane (Correct)
- **Option 2:** Epicranial structures (Incorrect, related to head structures)
- **Option 3:** Basement membrane (Incorrect, related to epithelial tissues)
- **Option 4:** None of these (Incorrect)

6. **Conclusion:**
- The correct answer is **arthrodial membrane**.

### Final Answer:
The thin and flexible membrane that joins sclerites together is called the **arthrodial membrane**.