Question

Match List-I with List-II

List-I (Type of Immunoglobulin)	List-II (Features)
(A) IgA	(I) Associated with inflammation and allergy
(B) IgG	(II) Major immunoglobulin of chicken
(C) IgY	(III) Present in external secretions and concerned with mucosal immunity
(D) IgE	(IV) Present in bovine colostrum and associated with secondary immune response

Choose the correct answer from the options given below

• (A) - (I), (B) - (IV), (C) - (II), (D) - (III)
• (A) - (III), (B) - (IV), (C) - (II), (D) - (I)
• (A) - (III), (B) - (I), (C) - (IV), (D) - (II)
• (A) - (III), (B) - (II), (C) - (I), (D) - (IV)

Hint:

To confirm this match:
- IgY is uniquely the major immunoglobulin of chickens and birds (C-II).
- IgE is always associated with allergies and type-I hypersensitivity (D-I).
These two distinct associations quickly identify the correct option.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Immunoglobulins (antibodies) are specialized glycoproteins synthesized by plasma cells that play a key role in the adaptive immune system. Different classes of immunoglobulins have unique structures and functions.

Step 2: Detailed Explanation:
Let us analyze and pair each immunoglobulin class with its corresponding feature:

(A). IgA: This is secretory immunoglobulin. It exists primarily as a dimer in external secretions (such as saliva, tears, colostrum, and gastrointestinal mucus) and provides crucial local mucosal immunity against pathogens at mucosal surfaces. Thus, (A) matches with (III).

(B). IgG: In mammals, IgG is the most abundant systemic immunoglobulin. It is concentrated in bovine colostrum to provide passive immunity to newborn calves, and is the primary antibody responsible for the secondary (anamnestic) immune response upon re-exposure to an antigen. Thus, (B) matches with (IV).

(C). IgY: This is the major systemic immunoglobulin found in birds, reptiles, and amphibians. It is the functional equivalent of mammalian IgG and is found in high concentrations in chicken egg yolk. Thus, (C) matches with (II).

(D). IgE: This immunoglobulin binds to Fc receptors on mast cells and basophils. It triggers the release of histamine and other vasoactive amines, mediating allergic reactions, anaphylaxis, and inflammatory responses against parasitic infections. Thus, (D) matches with (I).
Combining these matches, we obtain the sequence: (A) - (III), (B) - (IV), (C) - (II), (D) - (I).

Step 3: Final Answer:
The correct option is (B).