Question

Osphradium is a structure in Pila/mollusca. It is a
A) Sensory organ to smell and chemicals/ chemoreceptor
B) Sensory organ for balancing
C) Swimming organ
D) Locomotory organ

Answer 1

Hint:-The osphradium is an olfactory organ present in mollusks and pila. The main function of this organ is thought to be to test incoming water for silt and possible food particles. The presence of an osphradium is a type of molluscan synapomorphy. However, monoplacophorans and cephalopods lack osphradium.

Complete Answer:-
Pila has a single gill-like osphradium in the left pulmonary area. It is used to detect materials entering gills and hangs from the roof of the mantle cavity. In mollusk, a single or paired sensory attachment to the visceral ganglia is called osphradium. The major function of osphradium is to test the incoming water for silt and food particles. The osphradium also acts as an olfactory organ in certain mollusks and is linked with the respiratory organ. Osphradium structure resembles the feather of a bird and is also called Bipectinate. Chemoreceptors are used to detect chemical changes in the surroundings. It is found in the genus Conus- the cone snails and the predatory sea snails.
Thus, the right option is A.

Note:- Other than bivalves, many mollusks possess sensory organs which include a pair of eyes and tentacles. Whereas, mussels have statocysts and sensory osphradia that function as sensory osphradia (chemoreceptors). Chemoreceptors also help in maintaining appropriate oxygen, carbon dioxide, and pH in the body by coordinating various cardiovascular and respiratory reflexes. Examples include taste buds, carotid bodies and aortic bodies present in the human body detect changes in chemicals and pH value inside the human body.