The type of circulatory system in Periplaneta is

Options

A. Lacunar
B. Fenestrated
C. Peritrophic
D. Closed

Answer

**Step-by-Step Solution:**

1. **Identify the Organism**: The question refers to Periplaneta, which is commonly known as the cockroach.

2. **Understand Circulatory Systems**: There are two main types of circulatory systems in animals: open and closed. In an open circulatory system, the blood is not confined to blood vessels and bathes the organs directly. In a closed circulatory system, the blood circulates within a network of vessels.

3. **Determine the Circulatory System in Cockroaches**: Cockroaches, including Periplaneta, possess an open circulatory system. This means that their blood (hemolymph) is not contained within vessels but instead flows freely in the body cavity, bathing the organs directly.

4. **Clarify the Terms**:
- "Lacunar" refers to an open circulatory system where blood fills spaces (lacunae) around the organs.
- "Fenestrated" refers to tiny blood vessels, which are not present in cockroaches.
- "Peritropic" refers to a membrane that surrounds food boluses, which is not related to the circulatory system.
- "Closed" refers to a system where blood is contained within vessels, which is not applicable to cockroaches.

5. **Select the Correct Option**: Based on the understanding that cockroaches have an open circulatory system, the correct answer is "lacunar".

**Final Answer**: The type of circulatory system in Periplaneta (cockroach) is an open circulatory system, also referred to as lacunar.

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