Question

The cell mediated immunity inside the human body is carried out by
A. T-lymphocytes
B. B-lymphocytes
C. Thrombocytes
D. Erythrocytes

Answer 1

Hint: Cell mediated immunity is that type of immune response where there is no involvement of antibodies which are formed from B-lymphocytes and there is activation of phagocytes.

Complete answer:
First of all, you should know about cell mediated immunity. After the initial response to a specific type of pathogen, acquired immunity creates an immunological memory which leads to a better response while encountering that pathogen.
The acquired immunity includes both the humoral immunity and cell mediated immunity where humoral immunity is mediated by macromolecules which are found in extracellular fluids and antibodies are formed by B-lymphocytes.
Cell mediated immunity is that immune response where antibodies are not involved but there is activation of phagocytes, T-lymphocytes. Also, there is release of cytokines in response to an antigen.
If we look at options now, option A is T-lymphocytes. This is the correct option as the cell mediated immunity inside the human body is carried out by T-lymphocytes and there are no antibodies involved. Therefore, this option is the correct one.
Moving to option B i.e., B lymphocytes. This option is incorrect as humoral immunity is mediated by macromolecules found in antibodies which are formed by B-lymphocytes but in the option about cell mediated immunity is asked which is carried by T-lymphocytes not B-lymphocytes. Therefore, this option gets eliminated.
Option C is Thrombocytes. Thrombocytes are platelets and this option is incorrect as cell-mediated immunity inside the human body is carried out by T-lymphocytes not platelets and thus this option gets eliminated.
Last option D is Erythrocytes. Erythrocytes are red blood cells which contain hemoglobin and it imparts red color to blood and also helps to transport oxygen and carbon dioxide to and from the tissues. This option is incorrect as cell-mediated immunity inside the human body is carried out by T-lymphocytes not platelets and thus this option gets eliminated.

Hence, the correct answer is option (A).

Note: There are no antibodies involved in cell-mediated immunity and antibodies are formed from B-lymphocytes and in this type of immune response, there is activation of phagocytes and T-lymphocytes due to which option i.e., T-lymphocytes is the correct option.