Grade Six Science

From 4B

6. How does oxygen reach animals living in soil and water?

Air fills the space between the soil particles. The air between soil particles supplies oxygen to the animals that live there.

Aquatic animals and plants use dissolved oxygen in the water.

7. Why does the transparent glass of windows become hazy if it is not cleaned regularly?

Dust particles in the air adhere to the clear glass of windows. These particles also attract other elements, such as pollen, which collects on glass. As a result, if the windows’ transparent glass is not wiped regularly, it appears hazy.

8. What are the functions of long chimneys in factories?

When fuel is burned, smoke is produced. Frequent smoke is harmful because it contains a few gases and fine dust particles. Long chimneys in factories keep harmful gases and smoke away from the people living near the factory. 9. Why do our nostrils have fine hair and mucus? Why is it not recommended to breathe in through the mouth?

The air contains dust particles. Inside the nose, fine hair and mucus prevent dust particles from entering the respiratory system.

Dust particles may enter our respiratory tract if we breathe through our mouth because it lacks these dust barriers (fine hair and mucus). Hence, breathing through the mouth is not advised.

10. Why do animals that live deep in the soil come to the surface during heavy rains?

Animals that live in the soil obtain oxygen for breathing (or respiration) from the air that exists between the soil particles. When it rains heavily, water fills the spaces in the soil occupied by the air. In this situation, the animals living within the soil must emerge from the soil to breathe. Earthworms, for example, emerge from the soil only during heavy rains

So long for now; goodbye, Boys and Girls!