Question

Given below are the groups of certain substances of particular categories. Mention the category of each group and identify the one wrong example in it. Give reasons. [4 MARKS]
(a) Benzoic acid, DDT, mercurochrome.
(b) Formalin, iodine, lysol, phenol.
(c) BCG, DTP, ATP.
(d) Tears, skin, nasal secretion, HCI(in stomach).

Answer 1

Each Part: 1 Mark

(a) DDT - Others are antiseptics that are mild chemical substances which kill germs, when applied on the human body. DDT is a chemical pesticide used to eradicate disease-carrying and crop-eating insects.

(b) Iodine - Others are disinfectants, strong chemical substances that are applied on spots and places where germs thrive and multiply. They should not come in contact with human skin. Iodine is an essential trace element that is involved in growth-controlling and other metabolic functions.

(c) ATP - Others are vaccines or germ substances, artificially introduced into the body for developing resistance against particular diseases. ATP is a chemical compound found in all living organisms that release energy for cellular reactions.

(d) Skin - Others are germ-killing secretions. Skin serves as a protective mechanical barrier against the action of physical, chemical and bacterial agents on the deeper tissues.