Match the cell type (Column I) with its function (Column II).
Column I: P. B cells; Q. Neutrophils; R. T cells; S. Mast cells
Column II: 1. Humoral immunity; 2. Cytotoxicity; 3. Histamine-associated allergy; 4. Phagocytosis
P-1, Q-2, R-3, S-4
P-1, Q-4, R-2, S-3
P-4, Q-3, R-1, S-2
P-4, Q-3, R-2, S-1
ANSWER
Option (B): P-1, Q-4, R-2, S-3.
Official answer: BSource: Official answer key, GATE 2022 BT (IIT Kharagpur)
B cells differentiate into plasma cells that secrete antibodies into blood and body fluids. This is humoral immunity, so P matches 1.
Neutrophils are the most abundant circulating phagocytes. They engulf and destroy bacteria early in an infection, so Q matches 4 (phagocytosis).
Cytotoxic T cells () kill virus-infected and tumour cells using perforin and granzymes, so R matches 2 (cytotoxicity).
Mast cells carry IgE bound to their surface receptors. On allergen exposure they degranulate and release histamine, so S matches 3 (histamine-associated allergy).
The combination is P-1, Q-4, R-2, S-3, which is option (B).
Option (A) fails because it pairs neutrophils with cytotoxicity (Q-2), T cells with allergy (R-3) and mast cells with phagocytosis (S-4). Option (C) fails because it pairs B cells with phagocytosis (P-4). Option (D) fails because it pairs B cells with phagocytosis (P-4) and mast cells with humoral immunity (S-1).
KEY IDEA
Match each immune cell to its signature role. B cells make antibodies (humoral immunity). Neutrophils are phagocytes. Cytotoxic T cells kill infected cells. Mast cells release histamine in IgE-mediated allergy.
WATCH OUT FOR
Giving cytotoxicity to neutrophils because they kill microbes. Neutrophils kill by phagocytosis, while cytotoxicity as a cell-type function belongs to T cells (and NK cells). Another slip is linking mast cells to humoral immunity because they carry IgE, although they only bind antibody made by B cells.
From the GATE 2022 BT paper. Every question of this paper · Download the full paper · All 6 Immune system questions, with notes
