Match List – I with List – II.

Choose the correct answer from the options given below:

(A)-(III), (B)-(IV), (C)-(II), (D)-(I)

The correct answer is Option (2) → (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

A. When ready-made antibodies are directly given to protect the body against foreign agents, it is called passive immunity.  The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant.

B. The exaggerated response of the immune system to certain antigens present in the environment is called allergy. The substances to which such an immune response is produced are called allergens. The antibodies produced to these are of IgE type. Common examples of allergens are mites in dust, pollens, animal dander, etc. Symptoms of allergic reactions include sneezing, watery eyes, running nose and difficulty in breathing. Allergy is due to the release of chemicals like histamine and serotonin from the mast cells. 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.

C. Passive immunization refers to the administration of preformed antibodies directly into the body to provide immediate protection against specific pathogens or toxins. These antibodies are obtained from a donor who has already developed immunity to the target antigen. The injected antibodies provide temporary protection and do not stimulate the body's immune system to produce its own antibodies.

D. T-lymphocytes, also known as T-cells, are a type of white blood cell involved in cell-mediated immunity. They recognize and destroy infected or abnormal cells directly, respond to specific antigens presented by other cells, and play a crucial role in coordinating and regulating the immune response. B-lymphocytes, on the other hand, are responsible for humoral immunity by producing antibodies that target pathogens or foreign substances in body fluids.