The inner most elongated cells of ommatidium are 

Options

A. rhabdomere
B. cone cells
C. photoreceptor cells
D. cornea

Answer

To solve the question regarding the innermost elongated cells of the ommatidium, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Ommatidia**:
- Ommatidia are the basic structural units of the compound eye found in insects, such as cockroaches. Each ommatidium is composed of several types of cells that play specific roles in vision.

2. **Identify the Types of Cells in Ommatidia**:
- The main types of cells found in an ommatidium include:
- Corneogen cells: These are responsible for secreting the cornea, which is the outermost layer of the eye.
- Raptomeres: These are elongated cells and are the innermost cells of the ommatidium.
- Cone cells: These cells are involved in light vision but are not the innermost cells.
- Photoreceptor cells: These cells contribute to the overall sight but are not classified as the innermost cells.

3. **Determine the Function of Each Cell Type**:
- Corneogen cells → Secrete the cornea (outermost layer).
- Raptomeres → Elongated and innermost cells.
- Cone cells → Help in vision under light conditions.
- Photoreceptor cells → Aid in overall sight.

4. **Identify the Correct Answer**:
- Since the question specifically asks for the innermost elongated cells of the ommatidium, the correct answer is **raptomere**.

### Final Answer:
The innermost elongated cells of ommatidium are **raptomere**.

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