Question

Ocelli or fenestrae of cockroach take part in

• A. Sight
• B. Perception of temperature
• C. Perception of light
• D. Perception of humidity

Answer 1

The correct option is C

Perception of light

The correct option is C.

Explanation of the correct option:

1. On either side of the eye, close to the base of the antennae, are two circular regions known as ocelli.
2. Each region serves as a basic eye and is in charge of sensing light.
3. Only one lens makes up the ocelli, which also houses a retina that is disorganized and packed.
4. The ocelli are unable to produce an image because the focus point of the ocular lens is located behind the retina.
5. The primary function of the ocelli is to detect minute variations in light intensity and aid the organism in its direction.

Explanation of the incorrect options:

Option A:

1. The perception of light serves numerous purposes, including as sensors for ambient light intensity and for the transmission of related data to various sensory and neurological system regions.

Option B:

1. Thermoreceptors are present on the pads between the first four tarsals.
2. They can sense changes in temperature.

Option D:

1. Cockroaches exist in several habitats ranging from dark areas to minimal lighting areas.
2. The body of cockroaches bears several receptors that help in surviving them in these areas and perceive different types of stimuli such as touch, smell, and changes in the environment.

Final answer: Ocelli or fenestrae of cockroaches take part in the perception of light.