WAEC Biology 2020 Theory — Question 2

Model answer

(a)(i) A deficiency disease is a disease that occurs as a result of lack of important nutrient(s). (ii) Nutrient Deficiency Disease and Remedy: Kwashiorkor - the child should be fed with food with adequate amount of protein. Scurvy - intake of food that is rich in vitamin C. Night blindness - intake of food that is rich in vitamin A. Beriberi - intake of food that is rich in Vitamin B1. Rickets - intake of food that is rich in calcium and vitamin D. Goitre - intake of food that is rich in iodine. (b)(i) Test for starch in a tuber of yam: After the tuber of yam is peeled and sliced, few drops of iodine solution should be added. A blue-black colouration confirms the presence of starch. (ii) Test for glucose in orange fruit: The juice of the orange should be squeezed and then Fehling's reagent should be added. The mixture should then be gently heated. Formation of a brick-red precipitate shows the presence of glucose.