WAEC Biology 2023 Theory — Question 4

Model answer

(c)(i) Buccal cavity: takes in/receives food; contains the teeth that chew/masticate food to increase the surface area of food particles; contains salivary glands that secrete saliva that moistens the food and contains the enzyme ptyalin which breaks down starch to maltose. (ii) Duodenum: receives the food as chyme from the stomach; receives pancreatic juice from the pancreas; receives bile from the liver which reduces surface tension/emulsifies fats and oil. (iii) Stomach: temporarily stores food; secretes dilute hydrochloric acid which destroys bacteria; churns food. (d) The end product of adding dilute hydrochloric acid to sucrose is glucose and fructose.