Page 22 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

4. Name the part of Amoeba which helps it in moving and capturing food. Explain in

brief.
Ans. Amoeba protrudes tiny finger-like projections called pseudopodia or false feet that

help it in movement and to capture the food.
Firstly amoeba engulfs the food with the help of pseudopodia. The food is then

trapped inside a food vacuole where digestive juices are secreted. These juices help
break down the complex food into simpler form. Now, the digested food is absorbed

by the amoeba. It is then used to carry out various life processes. The unwanted
matter in then expelled out by the vacuole by rupturing the cell membrane.

5. What is the role of the gall bladder?

Ans. The gall bladder is a small organ located beneath the liver. Its primary role is to

store and concentrate bile, a digestive liquid produced by the liver. Bile helps in the
digestion of fats. When we consume a meal containing fat, the gall bladder release

bile into the small intestine to aid in breaking down and absorbing these fats.

6. What is saliva?
Ans. Salvia is a liquid produced by the salivary glands in the mouth. It plays a crucial

role in digestion and oral health. It moistens the food, making it easier to chew and

swallow. It also contains enzymes. Such as amylase, which helps in breaking down
carbohydrates into simple sugar.Saliva also helps to cleanse the mouth and killing

germs and microbes with the help of another enzyme called lysozyme.
7. How can we prevent tooth decay?

Ans. We can prevent tooth decay by following the below given points ?

• We should brush teeth twice daily with fluoride tooth paste.
• We should floss daily.

• Limiting sugary foods and drinks can prevent tooth decay.
• Visit the dentist regularly.

• We should eat a balanced diet.

• Smoking and chewing tobacco should be avoided to prevent tooth decay.

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