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प्रश्न
Open your mouth, look into a mirror and try to count the different types of teeth in your mouth. Compare them with Figure 2.3 on page 13 of your NCERT textbook. Record your observations in the table below:
| Type of teeth | Number of teeth | |
| In my mouth | In the figure | |
| Incisors | ||
| Canines | ||
| Premolars | ||
| Molars | ||
- Did you observe any difference in the number of teeth? If yes, could you identify which type of teeth showed the difference?
- Compare the number and type of teeth in an adult (say your parents or cousins who have reached the age of 25-30 or more). Note your observation.
उत्तर
| Type of teeth | Number of teeth | |
| In my mouth | In the figure | |
| Incisors | 8 | 8 |
| Canines | 4 | 4 |
| Premolars | 8 | 8 |
| Molars | 8 | 12 |
- Yes, molar teeth showed a difference in the number of teeth.
- A child (of class 7) has 8 incisors, 4 canines, 8 premolars and 8 molars in his mouth whereas an adult who has reached the age of 25-30 has 8 incisors, 4 canines, 8 premolars and last 4 molars are added after the age of 18 years in most human beings.
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संबंधित प्रश्न
Say true or false.
Brush your teeth once a day.
Tick (✓) the foods that are good for your teeth and cross (x) the food that is bad for your teeth.
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Number of teeth present in each jaw is ______.
Match the Column I with Column II and select the correct option.
| Column I | Column II |
| i. Heterodont | a. Teeth embedded in separate sockets in jaw bone |
| ii. Diphyodont | b. Four sets of teeth |
| iii. Thecodont | c. Two sets of teeth in lifetime |
What is milk teeth?
Name the four types of the permanent teeth.
How do you take care of your mouth and teeth?
Teeth are rooted in separate ______ in between the ______.
Write a note on the teeth of humans.
Collect data from your friends, neighbours and classmates to know more about “milk teeth".
Tabulate your data. One way of doing it is given below:
| S.No. | Age at which first tooth fell | Age at which last tooth fel | No. of teeth lost | No. of teeth replaced |
| 1. | ||||
| 2. | ||||
| 3. | ||||
| 4. | ||||
| 5. |
Find out from at least twenty children and find the average age at which children lose the milk teeth. You may take help of your friends.
