Ommatidia serve the purpose of photoreception in (a) cockroach (b) frog (c) humans (d) sunflower.
Option A In cockroach, the compound eyes are a pair of large, black, kidneyshaped organs situated dorsolaterally on the head, one on either side. Their surface is marked by a large number of hexagonal areas, the facets. Each facet represents a visual unit named ommatidium. The eyes are the organs of sight (photoreception).
