Periplaneta americana is also known as American cockroach. Which of the following information abuot it is incorrect?

Options

A. Number of wings = 2 pairs
B. Number of legs = 3 pairs
C. Type of circulatory system = closed type
D. Number of ovaries = 2

Answer

To determine which information about Periplaneta americana (the American cockroach) is incorrect, we will analyze each option provided in the question step by step.

### Step 1: Analyze the first option
**Option 1: Number of wings is two pairs.**
- Cockroaches have two pairs of wings. The forewings (or tegmina) are present in the mesothorax, and the hindwings are present in the metathorax.
- **Conclusion:** This statement is correct.

### Step 2: Analyze the second option
**Option 2: Number of legs is three pairs.**
- Cockroaches have three pairs of legs, with one pair on each thoracic segment: one pair on the prothorax, one pair on the mesothorax, and one pair on the metathorax.
- **Conclusion:** This statement is correct.

### Step 3: Analyze the third option
**Option 3: Type of circulatory system is closed.**
- Cockroaches have an open circulatory system, meaning their blood (hemolymph) flows freely through cavities called sinuses rather than being confined to vessels as in a closed circulatory system.
- **Conclusion:** This statement is incorrect.

### Step 4: Analyze the fourth option
**Option 4: Number of ovaries is 2.**
- Female cockroaches have two ovaries, which is a characteristic of their reproductive system.
- **Conclusion:** This statement is correct.

### Final Conclusion
The only incorrect statement about Periplaneta americana is:
- **Option 3: Type of circulatory system is closed.**