The correct sequence for the perception of smell in mammals is?

A. chemicals –> olfactory nerve endings –> brain
B. dissolved chemicals –> nasal sensory cells –> brain
C. chemicals –> mucus membrane sensory cells –> brain
D. dissolved chemicals –> sensory cells –> olfactory nerve –> brain

Correct Answer:

Option D – dissolved chemicals –> sensory cells –> olfactory nerve –> brain

Explanation

In mammals(humans), the process of olfaction begins when volatile molecules enter the nasal cavity and activate receptors in the olfactory epithelium (OE). The olfactory receptor (OR) proteins are located in hair-like projections of the olfactory sensory neurons (OSNs).