Question

Given below are certain statements regarding the cellular barriers. Find out how many of the statements are wrong?

A, Eosinophils are associated with allergic reactions.
B. Basophil is a phagocyte which eats cellular remains.
C. Natural killer cells kill bacteria and virus infected cells.
D. Macrophages in tissue can phagocytose and destroy microbes.

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is A 1

All living organisms are gifted with the resistance to certain infections by birth itself. This is called innate immunity. One of the barriers that helps in innate immunity is cellular barrier, the presence of certain immune cells in our body which resist infections.

Eosinophils : They are a group of white blood cells associated with allergic reactions. They have a bilobed nucleus. So statement A is correct.
Basophils : They are a group of white blood cells which contain granules with heparin, histamine, serotonin etc. They are associated with inflammatory reactions. After encounter with antigen they release large quantities of these chemicals from the cells resulting in inflammatory reactions (redness and swelling in the area). They are not phagocytic cells so they cannot eat cell remains. So statement B is wrong.
Macrophages : The monocytes (white blood cells with kidney shaped nucleus) of the blood migrate into tissues and differentiates into macrophages. They are long-lived. They are strongly phagocytic (cell eating) to a wide variety of particulate materials such as microorganisms, dead cells, debris etc. Hence statement D is correct.

Natural killer cells (NK cells) : They are a type of large granular lymphocytes. These cells are called natural killer cells as they kill the target cells without the aid of antibodies. Natural killer cells kill bacteria and virus infected cells. Hence statement C is correct.