Question

The following statement is NOT true for the receptor binding site of a virus.

• A. Binds specifically to a cellular receptor.
• B. Cannot bind to neutralizing antibodies.
• C. Interacts with the cellular receptor leading to activation of endocytosis.
• D. Is composed of unique structural domains.

Hint:

Neutralizing = Blocks entry (usually at the binding site).

Answer 1

The Correct Option is B

Step 1: Concept
Viruses initiate infection by attaching to specific host cell surface molecules.

Step 2: Meaning
Neutralizing antibodies work by blocking this very attachment.

Step 3: Analysis
Statements A, C, and D are true: binding is specific, it often triggers endocytosis, and involves unique domains. Statement B is false because neutralizing antibodies are *specifically* defined as antibodies that bind to the virus's receptor-binding site (or nearby), physically preventing the virus from entering the cell.

Step 4: Conclusion
Because the binding site is a primary target for the immune system, the claim that it cannot bind to antibodies is incorrect. Final Answer: (B)