Question

Which of the following are chemoreceptors?
A. Taste receptors
B. Olfactory receptors
C. Auditory receptors
D. Both a and b

Answer 1

A chemoreceptor, also known as a chemosensor, is a specialised sensory receptor cell that generates a biological signal by transducing a chemical substance (endogenous or generated). If the chemoreceptor is a neuron, the signal may be in the form of an action potential; if the chemoreceptor is a specialised cell, such as taste receptors, or an internal peripheral chemoreceptor, such as the carotid bodies, the signal may be in the form of a neurotransmitter that can activate a nerve fibre.

Complete explanation:
Option A: A taste receptor is a type of biological receptor that helps with taste perception. Food and other chemicals interact with saliva and bind to taste receptors in the oral cavity and elsewhere when they enter the mouth. "Sapid" molecules are those that produce a taste experience.
So, option A is not correct.
Option B: Olfactory receptor, also known as smell receptor, is a protein that binds scent molecules and is important in the sense of smell (olfaction). Arthropods, terrestrial vertebrates, fish, and other creatures all have these receptors.
So, option B is not correct.
Option C: Auditory receptor cells (also known as hair cells) are recessed from the body's surface, similar to olfactory cells that detect odours. In the inner ear, sound waves are transformed into vibrations in a fluid, and these vibrations move the hair cells indirectly, which subsequently give electrical signals to the brain.
So, option C is not correct.
Option D: Chemical receptors are referred to as chemoreceptors. Chemical receptors are involved in both taste and smell. As a result, they are chemoreceptors.
So, option D is correct

Therefore, Option D) is the correct answer.

Note:
A chemoreceptor detects changes in the normal environment, such as an increase in carbon dioxide levels in the blood (hypercapnia) or a decrease in oxygen levels in the blood (hypoxia), and transmits that information to the central nervous system, which activates body responses to restore homeostasis.
Chemoreceptors in the central nervous system are related to the respiratory centres. As a result, ${H^ + }$ ions are produced in the CSF. When these regions are activated, alveolar ventilation increases.