Topics |
|---|
1. Write a short note on teeth.
Our teeth are hard, bone-like things in the upper and lower jaw. They help us to chew our food. They give shape to the part of the face around our mouth. Our teeth are the hardest part present in our body.
2. Which are the two types of teeth present in humans?
Human beings have two set of teeth. They are decidous teeth and permanent teeth.
3. What are deciduous teeth?
Deciduous teeth are teeth that appear and fall very early in life. They are replaced by the permanent set of teeth. Deciduous teeth are also known as milk teeth or baby teeth.
4. When are deciduous teeth formed?
Deciduous teeth are formed when a baby is seven and a half months old. When a baby is born, deciduous teeth are present deep in the jaws. There are 20 deciduous teeth, 10 in each jaw.
5. What are permanent teeth?
Permanent teeth appear when the deciduous teeth start falling. The first permanent teeth appears when a child around 6 to 7 years old. The last one appears when a person is about 21 years old. There are a set of 32 permanent teeth, 16 in each jaw. These teeth are bigger than the milk teeth.
6. How many types of permanent teeth are there?
There are four types of permanent teeth. They are known as incisors, canines, premolars and molars.
7. What are incisors?
There are 4 incisors in each jaw. They are teeth used mainly to bite food. They have sharp, cutting edges.
8. What are canines?
There are 2 canines in each jaw. They are used with incisors to bite and tear the food. They have sharp, pointed edges and look like a dog's canine.
9. Write a note on molars and premolars.
There are 4 premolars and 6 molars in each jaw. Premolars and molars are used to grind food. Molars look like premolar but are a bit larger.
10. What are teeth made of?
There are four different things which make up our teeth. They are pulp, dentine, enamel and cementum.
11. What is the role of enamel?
The hard and shiny white things which covers every tooth is called enamel. It protects the tooth from the bacteria which can cause dacay.
12. What is the role of cementum?
Cementum is the bone like connective tissue covering the root of a tooth. It protects the root of the tooth and assist support. This is called Cementum.
13. What are the 3 main functions of our tongue?
Our tongue has 3 main functions to perform. They are:
14. What are taste bud?
Taste buds are tiny bumps on our tongue. They help us to differentiate between the four basic tastes, sweet, sour, salty and bitter. There are nearly 10,000 tiny and bumps on our tongue.
15. What is the need of saliva in our mouth?
Taste buds can taste some food only when the food is mixed with saliva. The watery, sticky, colourless liquid that fills the mouth is saliva. It helps us digest our food and also kills bacteria that enter our mouth.
16. What are beaks?
Just as humans use their teeth to tear and grind food, birds use their beaks. Birds have different kinds of beaks.
17. Why do birds have different kinds of beaks?
Birds have different kinds of beaks because they have different food habits. For eg: a toucom lives on soft fruit. A parrot eats fruits and nuts. A crossbill picks the seeds from pine cones. The shape of a birds beak gives us a clue about the food it eats. A woodcock or woodpecker has a long beak.
18. What is the speciality of Jacanas claws?
Jacanas are water birds with extremely long to us and claws which allows them to walk on floating vegetation. As they walk from leaf to leaf of water lilly, they feed on insects, small fish and seed of acquatic plants.
19. What is dentine?
Under the enamel is a material called dentine. It makes up the main body of the tooth.
20. What is dental pulp?
At the tooth's centre is a space filled with dental pulp. This has blood vessels and nerves that keep the tooth alive. The dental pulp hurts when we get cavities.
