Question

Given below are two statements:
Statement I: Insect will not lose the vision completely if a few ommatidia are injured.
Statement II: Insects have compound eyes in addition to simple eyes.

• A. Both Statement (I) and Statement (II) are correct
• B. Both Statement (I) and Statement (II) are incorrect
• C. Statement (I) is correct but Statement (II) is incorrect
• D. Statement (I) is incorrect but Statement (II) is correct

Hint:

Insects are particularly good at detecting high-frequency motion. While humans see at about 60 frames per second, some insects can process up to 300 frames per second.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Insect vision is remarkably different from vertebrate vision. They possess complex sensory organs designed for motion detection and light sensing.
The primary visual organs are compound eyes, supplemented by simple eyes known as ocelli.
Detailed Explanation:
Analysis of Statement I:
A compound eye is made of hundreds or thousands of individual units called ommatidia.
Each ommatidium functions like a separate eye, capturing a small part of the visual field.
These individual images are processed by the brain to form a mosaic view.
Because the units are independent, the loss or damage of a few ommatidia only creates small blind spots.
It does not result in total blindness, much like a few dead pixels on a television do not make the entire screen black.
Thus, Statement I is correct.
Analysis of Statement II:
Most adult insects have two types of eyes.
Compound eyes are large and situated on the sides of the head; they are used for forming images and detecting movement.
Simple eyes (ocelli) are usually found in a triangle of three on the forehead (vertex).
Ocelli do not form images but are highly sensitive to light intensity and help in navigation and circadian rhythm.
Larval insects have lateral ocelli called stemmata.
Thus, Statement II is correct.

Step 2: Final Answer:
Both statements accurately describe the anatomy and physiology of insect vision.