(a) (i) Physical digestion by teeth breaks down food into smaller pieces. Explain the importance of food being physically broken down into smaller pieces.
(ii) State the name of one other part of the digestive system where physical digestion occurs in humans.
(b) (i) There are different types of human teeth. The boxes on the left contain diagrams of different types of human teeth. The boxes on the right contain the names of the types of human teeth. Draw one straight line from each box on the left to a box on the right to match each tooth to its name. Draw three lines.
(ii) Describe the function of molar teeth.
(c) Fig. 2.1 is a diagram of a human tooth.
State the names of the parts labelled A, B, C and D in Fig. 2.1.
▶️ Answer/Explanation
Ans:
(a)(i) Breaking food into smaller pieces increases surface area for enzymes to act, speeding up chemical digestion. For example, amylase works more efficiently on smaller starch particles.
(a)(ii) The stomach performs physical digestion through churning and mixing actions.
(b)(i) Correct tooth matches:
(b)(ii) Molars grind and crush food into a paste-like consistency for swallowing.
(c) Tooth structure labels:
A: Enamel (hard outer layer)
B: Dentine (bony tissue beneath enamel)
C: Pulp (contains nerves and blood vessels)
D: Cement (anchors tooth to jawbone)
(a) Fig. 2.1 is a diagram of a human tooth.
The boxes on the left contain the letters identifying the parts in Fig. 2.1.
The boxes on the right contain the names of some parts shown in Fig. 2.1.
Draw lines to link each letter to its correct name.
Draw four lines.
(b) Complete the sentences to describe the role of teeth in digestion.
The teeth are needed for ……………………………………… digestion.
They break down food into smaller ……………………………………… .
This increases the ……………………………………… area of the food for the action of biological
catalysts called ……………………………………… .
These biological catalysts are needed for ……………………………………… digestion.
(c) State the names of two different types of human teeth.
▶️ Answer/Explanation
2(a) 
(b) The teeth are needed for physical / mechanical digestion. They break down food into smaller pieces. This increases the surface area of the food for the action of biological catalysts called enzymes. These biological catalysts are needed for chemical digestion.
Explanation: Teeth mechanically break down food, increasing surface area for enzymes to act efficiently during chemical digestion.
(c) Any two from: incisor, canine, pre-molar, molar.
Explanation: Humans have four types of teeth—incisors (cutting), canines (tearing), premolars & molars (grinding).