Many candidates performed well in question 4 (a). The performance was poor in 4 (b) (i) and candidates just listed the stages of holozoic nutrition in humans without explanation. The expected answers are:

(b) (i) Functions of stomach of Humans
- The stomach temporarily stores food;
- stomach secretes gastric juice containing hydrochloric acid; pepsin and rennin;
- hydrochloric acid provides acidic medium for protein digestion;
- hydrochloric acid destroys harmful bacteria in the stomach;
- rennin solidifies /curdles milk;
- pepsin digests protein into peptides in the stomach
- large particles of food are turned and broken down to smaller particles by the contraction of the stomach muscle/churning.

(ii) Stages of holozoic nutrition

Ingestion; taking in pieces of solid food into the mouth
Digestion: breaking down of large food particles by mechanical/chewing; enzymatic activites/chemical means into smaller particles/soluble that the body can absorb.
Absorption: taking up the soluble products of digestion into the blood;
Assimilation: using/utilization of the absorbed food materials by the body cells/tissues; Egestion: elimination of the undigested food materials through the anus.

(c) Effects of indigestion in humans
- causes constipation/inability to defaecate;
- bloated stomach;
- stomach ache;
- heartburn/burning sensation;
- general weakness;
- flatulence/release of gas.