Observe the diagram and answer the following question.
What is indicated 'R' in the diagram?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) – Antigen binding site
When the VH and VL domains are paired in the antibody molecule, the hypervariable loops from each domain are brought together, creating a single hypervariable site at the tip of each arm of the molecule. This is the binding site for antigen, the antigen-binding site or antibody combining site.
