Answer:
i. Name each of the parts labelled I, II, III, IV and V. 
 {5 marks}
I - Crown / Enamel
II - Dentine 
III - Cement / Periodontal membrane 
IV - Jaw bone / Root 
V - Pulp Cavity 
ii What is the function of each of the parts labelled I and III?
 {2 marks}
I - Protects teeth from harmful bacteria 
-- Enable teeth withstand pressure of chewing 
-- Cutting / chewing / protects dentine / protect pulp cavity
III - hold tooth firmly (in socket / Jaw bone)
iii Which of the labelled parts could be affected by tooth decay?
 {1 mark}
V - Pulp cavity
iv State three ways by which tooth decay may be prevented.
 {3 marks}
→ avoid using sharp-pointed objects
→ avoid having dry mouth
→ use water containing fluorides to wash teeth / mouth 
→ avoid smoking 
→ the teeth should be cleaned regularly after each meal / remove food particle from the teeth / flossing 
→ wash the mouth vigorously after each meal
→ regular visit to the dentist
→ avoid eating too hot foods
→ avoid eating too much sugary food 
→ avoid eating too cold food / taking too cold drinks
Step-by-step explanation: