NEET BIOLOGY

Detailed explanation-1: -The compound eyes of arthropods like insects, crustaceans and millipedes are composed of units called ommatidia (singular: ommatidium). An ommatidium contains a cluster of photoreceptor cells surrounded by support cells and pigment cells. The outer part of the ommatidium is overlaid with a transparent cornea.

Detailed explanation-2: -Each compound eye of the cockroach is composed of up to 2000 visual units (ommatidia) of the fused rhabdom type. The ommatidia themselves consist of eight receptor cells which terminate as axons in either the first or second optic ganglion.

Detailed explanation-3: -The fly eye is comprised of several hundred unit-eyes that are also called ommatidia. These unit eyes are packed into a hexagonal array of remarkable precision. The structure of the eye is so precise that it has been compared to that of a crystal (Ready et al., 1976).

Detailed explanation-4: -A cockroach has compound eyes located on the lateral sides of the head, each in the form of a dark kidney-shaped structure formed of around 2000 hexagonal units called the ommatidia or simple eyes.

Detailed explanation-5: -Compound eyes of cockroach are large, black and kidney-shaped. It is situated dorsolaterally on the head. Eye consists of about 2000 similar hexagonal units called ommatidium, each capable of forming an image.