Question

Cockroach, house fly, and mosquitoes are insect because they have
A. Chitinous exoskeleton and body divided into head and cephalothorax
B. Six legs, ocelli, and a body divided into head, thorax, and abdomen
C. Segmented body with jointed feet and chitinous exoskeleton
D. 3 pairs of legs, one pair of antennae, and flame cells

Answer 1

Insects are organisms that have three combines of legs and two pairs of wings. The body consists of three elements called the head, thorax, and abdomen. The two antennae within the head region are the sensors for smell or olfaction. The members of Arthropods don't have wings and antennae.

Complete answer: Insects belong to the class Insect or Hexapod, any member of the largest class of the phylum Arthropod, which is itself the largest of the animal phyla.
-Insects with segmented bodies, jointed legs and outer exoskeletons. Insects are differentiated from other arthropods by their anatomy, which is separated into three main regions of the chitinous exoskeleton, a three-body part head, thorax, and abdomen, three pairs of jointed legs, one pair of antennas, and compound eyes.
-There are two antennas in the head area that are receptors for scent or smell. The members of the Arthropods do not even have wings and antennas. They have a compound pair of eyes called ocelli.
They also have many-segmented abdomen, which contains the excretory, digestive, and reproductive organs.
-Insects are the most diverse group of mammals, including more than one million described species and including more than half of all recognized living organisms.
Hence, the correct answer is an option C-'Segmented body with jointed feet and chitinous exoskeleton’.

Note: In several species the distinction in anatomical structure between the sexes is pronounced, and information of one sex might provide few clues to the looks of the opposite sex. In some, like the twisted-wing insects, the feminine may be a mere inactive bag of eggs, and therefore the winged male is one of the foremost active insects celebrated. Modes of copy area unit quite various and generative capability are usually high. Some insects, like the mayflies, feed solely within the immature or larval stage and go while not food throughout especially short adult life. Among social insects, queen termites might live for up to fifty years, whereas some adult mayflies live but 2 hours.