Humans get Acquired Immuno Deficiency Syndrome (AIDS) when _________ are attacked by Human Immuno Deficiency Virus (HIV).
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → T-helper cells
The white blood cells (leucocytes) of the immune system identify and destroy foreign bodies such as viruses. They include T cells, B cells and natural killer cells.
Option (1) Alpha cells — Incorrect. Alpha cells are cells of the pancreas that produce the hormone glucagon. They are not white blood cells of the immune system, so HIV does not target them (see the Note).
Option (2) B cells — Incorrect. B cells produce antibodies; they are not the target of HIV.
Option (3) T-helper cells — Correct. Among the white blood cells, T cells destroy invaders and T-helper cells increase immunological activity. It is these T-helper cells that are attacked by HIV, the virus causing AIDS, so the whole immune response weakens.
Option (4) Natural killer cells — Incorrect. These cells are involved in the fight against both viruses and tumours, and stress can lower their activity; but HIV’s target is the T-helper cell.
Note 1: The concept in Option (1), ‘alpha cells’, is not in NCERT (2025-26); explained here for the benefit of the students.
Note 2: A similar question was also asked in CUET (UG) 2026 on 29-05-2026 (Slot 2).
Note 3: A similar question was also asked in CUET (UG) 2023 on 23-06-2023 (Slot 3).
NCERT (2025-26): “Stress and the Immune System … There are several kinds of white blood cells or leucocytes within the immune system, including T cells, B cells and natural killer cells. T cells destroy invaders, and T-helper cells increase immunological activity. It is these T-helper cells that are attacked by the Human Immuno Deficiency Virus (HIV), the virus causing Acquired Immuno Deficiency Syndrome (AIDS). B cells produce antibodies. Natural killer cells are involved in the fight against both viruses and tumours.…” |