Which of the following is not a part of the respiratory system of Periplaneta americana ?

Options

A. Trachea
B. Sclerites
C. Spiracles
D. Both 'B' and 'C'

Answer

To solve the question "Which of the following is not a part of the respiratory system of Periplaneta americana?" we will follow these steps:

### Step 1: Understand the Respiratory System of Periplaneta americana
Periplaneta americana, commonly known as the American cockroach, has a unique respiratory system that primarily consists of a tracheal system. This system is adapted to transport air directly to the tissues without the need for respiratory pigments like hemoglobin.

**Hint:** Research the components of the respiratory system in insects, particularly in cockroaches.

### Step 2: Identify the Key Components of the Respiratory System
The main components of the respiratory system in Periplaneta americana include:
- **Tracheae:** These are tubes that carry air directly to the tissues.
- **Spiracles (or Stigmata):** These are openings on the surface of the cockroach that allow air to enter and exit the tracheal system.

**Hint:** Look for the specific structures involved in the respiratory process of cockroaches.

### Step 3: Analyze the Given Options
In the question, we need to determine which option is not part of the respiratory system. The options typically include terms like spiracles, tracheae, and possibly other structures like sclerites.

**Hint:** Compare the options with the known components of the respiratory system.

### Step 4: Identify the Incorrect Option
From the analysis, we know that:
- Spiracles and tracheae are essential parts of the respiratory system.
- Sclerites, on the other hand, are not involved in respiration; they are part of the exoskeleton providing support and protection.

**Hint:** Recall the definitions and functions of each term related to the cockroach's anatomy.

### Step 5: Conclusion
The component that is not part of the respiratory system of Periplaneta americana is **sclerites**. Therefore, the correct answer to the question is **sclerites**.

**Final Answer:** Sclerites are not a part of the respiratory system of Periplaneta americana.