Note: In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

Assertion : Receptor proteins show selectivity for one chemical messenger over the other.

Reason : Chemical messenger binds to the receptor site and inhibits its natural function.

• Receptors which are basically proteins do show selectivity for a certain chemical messenger due to the variety of in the shapes, structures and even their amino acid compositions.

• So different receptors interact with different types of chemical messengers

• The given reason statement is wrong as chemical messengers process communication b/w cells only do not pay any contribution to inhibition of any natural functions of the receptors.