Question

In cockroaches, air enters the body through
A) Lungs
B) Gills
C) Spiracles
D)Skin

Answer 1

Hint: The respiratory organ of a cockroach is called tracheae. It is a highly efficient system due to which it can hold its breath for several minutes.

Complete answer:
Respiratory system of insects is different from that of humans. Here we are going to discuss the respiratory system of cockroaches which is very different from that of other insects. Their respiratory organ comprises the tracheal system. Trachea is a tube like structure which helps to conduct air. They take oxygen from the surrounding by the small holes present on the lateral surface of the body. The air is taken in by the help of spiracles that conduct air through the tracheal tube. The opening and closing is controlled by sphincter muscles. The air is conducted to tracheoles.
Lungs- Human beings respiratory system consists of lungs. Frogs also breathe through lungs in land.
Gills- Gills are the respiratory organ found in aquatic animals like fishes. Gills are specialised to utilise dissolved oxygen.
Skin- Skin is the respiratory organ in earthworms. The moist skin helps in exchange of gases.
Thus the correct answer is (C). Air enters through spiracles in cockroaches.
Additional Information: Respiratory system of cockroaches is similar to that of humans. Spiracles are similar to nostrils in function; trachea is present in both the system; Tracheoles are similar to alveoli in function.

Note: Spiracles are a pair of openings present in the body of cockroaches. They conduct air from the environment to the trachea. They are similar to nostrils in function.