The unit of photoreception, in a compound eye of cockroach and other insects is

Options

A. Crystalline cone
B. Rhabdome
C. 0mmatidium
D. Facet

Answer

To answer the question about the unit of photoreception in the compound eye of a cockroach and other insects, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of the Compound Eye**:
- The compound eye of insects, including cockroaches, is made up of multiple small units called ommatidia. Each ommatidium functions as an individual photoreceptive unit.

2. **Identify the Components of an Ommatidium**:
- Each ommatidium consists of several components, including:
- **Crystalline Cone**: A conical structure that acts as a lens.
- **Rhabdom**: A cylindrical structure located at the center of the ommatidium, where photoreceptor cells are found.
- **Photoreceptor Cells**: These cells are responsible for detecting light.
- **Pigment Cells**: Surround the ommatidium and help in light absorption to prevent scattering.

3. **Determine the Correct Answer**:
- The question specifically asks for the unit of photoreception. The ommatidium is the entire unit that contains the photoreceptor cells and is responsible for photoreception in the compound eye.
- Therefore, the correct answer is **ommatidium**.

### Final Answer:
The unit of photoreception in the compound eye of the cockroach and other insects is the **ommatidium**.

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