Page 62 - ACTIVE SCIENCE 4 TOC

• Enamel is the hardest part of the body.

• Humans have two sets of teeth – the milk teeth and the permanent teeth.
• Milk teeth start falling between the age of 6 and 12 and permanent teeth start
growing in their place.

• Measures like brushing, gargling, avoiding junk food, sweets and chocolates, eating
healthy food, fruits, green vegetables, regular dental visit, etc., must be taken to
protect your teeth from germs.

• Calcium and vitamin C are very important for healthy and strong teeth.
• While eating food, little particles of food that remain stuck on the teeth can cause the
growth of bacteria.

• When we put food into our mouth, the digestive system starts working from that
very moment.
• We cannot see microbes with naked eyes. They can be seen using a microscope

because they are very tiny in size.
• Different microbes cause different diseases like typhoid, chicken pox, candidiasis, etc.
• Useful microbes help in preparing various food items and medicines.

Let’s Pronounce Together

dentine enamel fungi microbes saliva
canine protozoa intestine pancreas

Glossary

• Crown : The tooth above the gum which is visible.

• Neck : The part which is below the crown, touching the gum.
• Root : The part of the tooth inside the gum.
• Enamel : The hard outer covering of the tooth which is white in colour.

• Dentine : The layer below the enamel.
• Saliva : It is a digestive juice secreted in the mouth.

• Digestion : Breaking down of food into small particles so that it can be easily
absorbed by the body.

• Protozoa : Single-celled microbes.
• Microbes : Tiny living things.

• Fungi : These grow on dead and rotten matter.

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