Question

Select the correct option:
In the mouthparts of a cockroach, the labium forms ___________ (i) while _________ (ii) acts as a tongue.
a. (i)-upper lip; (ii)-maxilla
b. (i)-upper lip; (ii)-hypopharynx
c. (i)-lower lip; (ii)-maxilla
d. (i)-lower lip; (ii)-hypopharynx

Answer 1

The cockroach body is elongated and segmented. The color of the cockroach is dark or reddish-brown. The mouth of the cockroach is present on the head ventrally located. The parts of the mouth help in biting and chewing food. Sclerites are the calcareous plate in a cockroach which is exoskeleton thick and hard.

Complete answer:
The different mouthparts of the cockroach are the labrum, mandibles, maxillae, and labium.

Labrum – The dorsal side of the head capsule which is broad, flattened terminal sclerite, and can move articulated to the clypeus. This acts as an upper lip in the cockroach. On the inner side, epipharynx is present which is a chemoreceptor.

Mandibles – It is present beneath the labrum which is thick hard and triangular-shaped appendages. It is located on the mouth each lateral side and bears pointed teeth like projections called denticles.

First maxillae – It is situated next to the mandibles on each side of the mouth. It helps in cutting and chewing of the food. The olfactory receptors are also present in this.

Labium – It is the second maxillae that fuse and forms a single large structure. It covers the ventral side of the mouth and is called the lower lip or labium. Tactile and gustatory sensory setae are present in this part.

Hypopharynx – It is present between the first maxillae. The size of this is a small, cylindrical-shaped mouthpart and sand witches. It is covered by the dorsal and ventral side of the labrum and labium. On its free end, sensory seats are present that open in the common salivary duct upon its basal part. So it will act as a tongue.

In the mouthparts of a cockroach, the labium forms the lower lip while the hypopharynx acts as a tongue.

Hence, the correct answer is option (D).

Note: The mouthparts of cockroach are numerous and the function of every part differs. The chewing and cutting of food, tasting of food, etc. are the functions of the mouthparts of cockroaches. The body of the cockroach is divided into three parts named as head, thorax, and abdomen. The jointed appendages in cockroach are of 3 pairs and wings are of 2 in pairs.