Psychoneuroimmunology studies the effects of stress on the immune system. Identify the correct statements describing its working:
(A) The Leucocytes within the immune system identify and destroy antigens such as viruses
(B) Stress does not affect natural killer cell cytotoxicity
(C) Stress leads to the production of antibodies
(D) There are several kinds of Leucocytes including the T cells, B cells and natural killer cells
(E) D-cells produce antibodies
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A), (C) & (D) only
Note: The given answer is as per the official NTA Answer Key. However, there seems to be a mistake in the question. Statement (C) says that stress leads to the production of antibodies, while NCERT says that it is the immune system that leads to the production of antibodies. NTA has probably interpreted statement (C) as a line about the immune system, which psychoneuroimmunology studies, and so counted it as correct. Read strictly, only (A) and (D) are correct, and no option gives (A) and (D) alone; Option (3) is the only option that contains both of them, as explained below.
Psychoneuroimmunology focuses on the links between the mind, the brain and the immune system, and studies the effects of stress on the immune system. The statements describe how that system works.
(A) The Leucocytes within the immune system identify and destroy antigens such as viruses Correct. The white blood cells (leucocytes) within the immune system identify and destroy foreign bodies (antigens) such as viruses.
(B) Stress does not affect natural killer cell cytotoxicity Incorrect. Stress can affect natural killer cell cytotoxicity, which matters in the defence against infections and cancer; reduced levels are found in highly stressed people such as students facing important examinations and bereaved persons.
(C) Stress leads to the production of antibodies Correct as per the NTA answer key; however, it should have been Incorrect. It is the immune system that leads to the production of antibodies, and among its white blood cells it is the B cells that produce them. Stress does not produce antibodies; stress affects the working of the immune system, for example natural killer cell cytotoxicity.
(D) There are several kinds of Leucocytes including the T cells, B cells and natural killer cells Correct. These are the three kinds of white blood cells: T cells destroy invaders, B cells produce antibodies, and natural killer cells fight viruses and tumours.
(E) D-cells produce antibodies Incorrect. Antibodies are produced by the B cells; the immune system has no ‘D cells’ among its leucocytes.
NCERT (2025-26): “Stress and Immune System … Psychoneuroimmunology focuses on the links between the mind, the brain and the immune system. It studies the effects of stress on the immune system. How does the immune system work? The white blood cells (leucocytes) within the immune system identify and destroy foreign bodies (antigens) such as viruses. It also leads to the production of antibodies. 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. Stress can affect natural killer cell cytotoxicity, which is of major importance in the defence against various infections and cancer.…” |