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 one of the following is not the cellular barrier of innate immunity?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Hepatocytes
Innate immunity is the non-specific defence that is present at the time of birth. It has four kinds of barriers: physical, physiological, cellular and cytokine barriers. The cellular barriers are certain white blood cells (leukocytes) that phagocytose and destroy microbes.
Option (1) Monocytes — A cellular barrier of innate immunity. Monocytes are leukocytes of the blood. They engulf and destroy microbes that enter the body.
Option (2) Neutrophils — A cellular barrier of innate immunity. Neutrophils are the polymorpho-nuclear leukocytes (PMNL) of the blood. They are phagocytes and kill microbes after engulfing them.
Option (3) Hepatocytes — Not a cellular barrier of innate immunity. Hepatocytes are the cells of the liver. They are not leukocytes, and their work is the metabolic work of the liver. They do not phagocytose microbes; in malaria, Plasmodium even multiplies inside liver cells.
Option (4) Macrophages — A cellular barrier of innate immunity. Macrophages are large phagocytic cells found in the tissues. They engulf and destroy microbes there.
Note: 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.