MATCH THE COLUMNS Column A Column B 1. Respiration A. Cramps 2. Bronchioles B. Skin 3. Earthworm C. Epiblema 4. Roots D. Alveoli 5. Lactic acid E. Oxygen

1-E Respiration is a biochemical process that involves taking oxygen into the cells. The oxygen is then used to produce energy in the form of ATP molecules by the oxidation of the respiratory substrate, which is glucose. Carbon dioxide and water produced as by-products of this process are removed from the cells. 2-D The trachea divides into two bronchi to enter both the lungs. In the lungs, bronchi are divided further into smaller tubes called bronchioles. On the other end of the bronchioles, there are very small sac-like structures called alveoli. These alveoli are surrounded by blood vessels and help in the exchange of respiratory gases. 3-B Earthworms breathe through their moist skin. The skin absorbs oxygen from the air through diffusion. The carbon dioxide from the tissues is diffused out to the exterior similarly. Thus, the respiratory organ of the earthworm is the skin. 4-C The outer surface of the roots, stem, leaves, etc., are covered with a layer of cells called epidermis. In the roots, some cells of the epidermis have cytoplasmic extensions to form the root hair. Such cells with root hairs are called the epiblema cells. 5-A The muscle cramps occur in the leg when we run fast because while running the muscular tissues in our legs experience a temporary deficiency of oxygen. During this time, the cells of the tissue perform anaerobic respiration in which the glucose is converted into lactic acid, and energy is released. The accumulation of lactic acid in muscles causes cramps in muscles. Column A Column B 1. Respiration E. Oxygen 2. Bronchioles D. Alveoli 3. Earthworm B. Skin 4. Roots C. Epiblema 5. Lactic acid A. Cramps