Read the following paragraph carefully and answer the given questions.
Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes. For determining the cause of allergy, the patient is exposed to or injected with very small doses of possible allergens, and the reactions studied. The use of drugs like anti-histamine, adrenalin and steroids quickly reduce the symptoms of allergy. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. This is obtained by acetylation of morphine. Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs. Different species of Plasmodium (P. vivax, P. malaria and P. falciparum) are responsible for different types of malaria. Of these, malignant malaria caused by Plasmodium falciparum is the most serious one and can even be fatal.
Which of the following technique is not very useful to detect the cancers of internal organs?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → ELISA
Cancers of the internal organs cannot be seen from outside. They are found with imaging techniques that show the inside of the body.
Option (1) X-rays — Very useful to detect cancers of internal organs. Radiography uses X-rays to show the organs. A tumour shows up as an unusual mass on the X-ray film.
Option (2) Magnetic resonance imaging — Very useful to detect cancers of internal organs. It uses strong magnetic fields and non-ionising radiation to find pathological and physiological changes in living tissue.
Option (3) ELISA — Not very useful to detect cancers of internal organs. ELISA (enzyme linked immuno-sorbent assay) is an antigen–antibody test. NCERT names it for finding a pathogen such as HIV, not for imaging organs.
Option (4) Computed tomography — Very useful to detect cancers of internal organs. It uses X-rays to build a three-dimensional image of the inside of an organ.
Note 1: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.
Note 2: A similar question was also asked in CUET (UG) 2026 on 31-05-2026 (Slot 2).