The functional units of compound eye of an insect are called

Options

A. Fenestrae
B. Ocelli
C. Radula
D. Ommatidia

Answer

To solve the question regarding the functional units of the compound eye of an insect, we can follow these steps:

### Step 1: Understand the Structure of Insect Eyes
Insects have a unique type of eye known as a compound eye. Unlike the simple eyes of other animals, compound eyes are made up of multiple small units.

### Step 2: Identify the Functional Unit
The functional units of the compound eye are called ommatidia. Each ommatidium consists of a cluster of photoreceptor cells that work together to detect light and form images.

### Step 3: Analyze the Options
Given the options:
1. Phanestral
2. Uceli
3. Radula
4. Ommatidia

We can eliminate the incorrect options:
- Phanestral and Uceli are not related to insect eyes.
- Radula is a structure found in mollusks, not insects.

### Step 4: Confirm the Correct Answer
The only option that correctly identifies the functional unit of the compound eye in insects is **Ommatidia**.

### Final Answer
The functional units of the compound eye of an insect are called **Ommatidia**.

---