Question

Head of a housefly bears .......... compound eyes.
(a) One
(b) Two
(c) Three
(d) Four

Answer 1

Hint: The housefly (Musca domestica) belongs to the Cyclorrhapha suborder of flies. It is thought to have originated in the Cenozoic Era, possibly in the Middle East, and has since spread throughout the world as a human commensal. It is the most common fly found in residences. Adults have a single pair of membranous wings, four dark longitudinal lines on the thorax, and a slightly hairy body.

Complete answer:
In arthropods like insects and crustaceans, a compound eye is a visual organ. It could have thousands of ommatidia, which are tiny photoreceptor cells that distinguish brightness and color and are made up of cornea, lens, and photoreceptor cells.
The image seen by this arthropod eye is made up of inputs from a variety of ommatidia, each of which is oriented in a slightly different direction. The pair of large compound eyes in male house flies almost touch but are more widely separated in females. Three simple eyes (ocelli) and a pair of short antennae are all they have. Compound eyes have poor image resolution when compared to single-aperture eyes, but they have a large view angle and the ability to detect fast movement and, in some cases, light polarization.
Apposition eyes, which form multiple inverted images, and superposition eyes, which form a single erect image, are the two most common types of compound eyes.
Since compound eyes lack a well-developed brain to analyze the formed image, they primarily provide a mosaic pattern of vision. The image is made up of ommatidia, which are repeating units. The housefly's head has two compound eyes.

Thus, the answer is option B.

Note: A simple eye (also known as a pigment pit) is a type of eye or optical arrangement that consists of a single lens and no elaborate retina, as seen in most Vertebrates. In this sense, a "simple eye" differs from a multi-lens "compound eye," and is not necessarily simple in the traditional sense.