In cockroaches, the sclerite are joined to each other by

Options

A. a thin and flexible articular membrane.
B. the thin and flexible muscles of the targites .
C. the thin and flexible muscles of the sternites .
D. the extended membrane of the wings.

Answer

To solve the question "In cockroaches, the sclerites are joined to each other by," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Cockroaches**:
- Cockroaches belong to the phylum Arthropoda and have a segmented body divided into three main regions: head, thorax, and abdomen.

**Hint**: Remember that cockroaches are arthropods, which means they have an exoskeleton and segmented bodies.

2. **Identify the Exoskeleton Components**:
- The cockroach's body is covered by a hard exoskeleton made of chitin. This exoskeleton consists of hardened plates known as sclerites.

**Hint**: Sclerites are the hard plates that form the exoskeleton of the cockroach.

3. **Differentiate Between Tergites and Sternites**:
- The sclerites include tergites (the dorsal plates) and sternites (the ventral plates). Together, these are referred to as sclerites.

**Hint**: Tergites are on the back (dorsal), while sternites are on the belly (ventral).

4. **Determine How Sclerites are Joined**:
- The sclerites are connected to each other by a thin and flexible articular membrane. This membrane allows for movement between the sclerites.

**Hint**: Look for the flexible connection that allows movement; it’s not muscles but rather a membrane.

5. **Evaluate the Answer Choices**:
- Based on the information, the correct answer is that sclerites are joined by a thin and flexible articular membrane. The other options (muscles of tergites, thin and flexible muscles of sternites, extended membranes of the wings) are incorrect.

**Hint**: Cross-check the options against the information about how sclerites are connected.

### Final Answer:
The sclerites in cockroaches are joined to each other by a thin and flexible articular membrane.