Which one of the following regions of the alimentary canal in periplaneta is characterised by the presence of a peritrophic membrane.

Answer

To answer the question about which region of the alimentary canal in Periplaneta (the genus of cockroaches) is characterized by the presence of a peritrophic membrane, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the specific region of the alimentary canal in Periplaneta that has a peritrophic membrane.

2. **Identify Periplaneta**: Recognize that Periplaneta refers to a genus of cockroaches. This is important as it helps us focus on the anatomy of cockroaches.

3. **Define Peritrophic Membrane**: The peritrophic membrane is a specialized membrane that lines the guts of certain animals and arthropods. It serves to separate the ingested food from the gut epithelium.

4. **Locate the Region in Cockroaches**: In cockroaches, the peritrophic membrane is specifically found in the mid-gut region of the alimentary canal.

5. **Function of the Peritrophic Membrane**: The peritrophic membrane protects the mid-gut wall from hard food particles, ensuring that the gut epithelium is not damaged by the food being processed.

6. **Conclude the Answer**: Therefore, the region of the alimentary canal in Periplaneta characterized by the presence of a peritrophic membrane is the **mid-gut**.

### Final Answer:
The region of the alimentary canal in Periplaneta characterized by the presence of a peritrophic membrane is the **mid-gut**.

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