Chapter 37, Problem 2STP

Summary Introduction

Introduction:

Antigen is a structure specifically bound by antibodies or a cell- surface version of antigen receptor.

Answer to Problem 2STP

Correct answer:

The correct answer is option (A) 1.

Explanation of Solution

Explanation/justification for the correct answer:

Option (A) 1. They allow for an enormous number of possible antibodies to form. Antibodies are immunoglobulin’s that contains four polypeptides that are two heavy chains and two light chains. (2) and (3) are the variable regions that include the ends of the heavy and light chains. So, the correct answer is option (A).

Explanation for incorrect answer:

Option (B) 2. Antibodies are immunoglobulin’s that contains four polypeptide that is two heavy chains and two light chains. (2) And (3) are the variable regions that includes the ends of the heavy and the light chains. That is option (B) is not correct.

Option (C) 3. No, they do not help to reduce the number of antibodies they form. These are the variable on heavy and light chains. Hence, option (C) is not correct.

Option (D) 4. They allow for an enormous number of possible antibodies to form. Heavy-chain antibodies can bind antigens despite having only V H domains. So, option (D) is not correct.