Question

Antenna of cockroach have
A. Gustatory receptors
B. Auditory receptors
C. Tactile receptors
D. Tactile and olfactory receptors

Answer 1

Hint:-Since the cockroach waves them about, the antennae are also called 'feelers'. In fact, the antennae are the 'nose' insects - they are used for the sense of smell. A variety of individual joints make up the paired antennae. That implies that they can be very mobile.

Complete step-by-step solution:-
To study the multifunctional sensory appendage that generates the senses of olfactory, gustatory, tactile, thermal, and humidity, Cockroach antennas have been widely used. Of the spectrum of senses, it is assumed that the tactile sense plays a vital role in perceiving actual things. Since most species of cockroaches are nocturnal, it will be important to ascertain the location, shape and texture of nearby objects in the dark through the tactile sense of the antenna. The production of tactile sense is mainly responsible for mechanoreceptors on the surface of the antenna.

There are a number of mechanoreceptors for cockroach antennae that vary in morphology, position, and function. The antennal mechanoreceptors are morphologically categorised as follows: hair sensillum (or only hair), campaniform sensillum, and chordotonal sensillum.

The brain of the cockroach consists of three separate anteroposterior regions: protocerebrum, deutocerebrum, and tritocerebrum. The sensory data collected by the antennae is transmitted mainly to the deutocerebrum. Many anatomical studies have shown that in the ventral deutocerebrum and non-olfactory receptor afferents project, the olfactory receptor afferents primarily project to the main olfactory centre to other regions from the deutocerebrum to the subesophageal ganglion.The mechanosensory pathways have not been properly identified in any insect species, in comparison to the olfactory pathway.

So from these discussions we can conclude that the cockroach antenna has both tactile and olfactory receptors. Therefore the correct answer is option (D).

Note:-
 It was thought that the insect antenna was very non-responsive to escape behaviour. The reactivity, however, tends to depend on the stimulants' tactile role. For eg, if a cockroach is in contact with a possible intruder, it will automatically turn away and flee from the intruder as detected by the antenna.