HOW IS THE OXYGEN IN THE ATMOSPHERE REPLACED

Oxygen is product during the process of photosynthesis. In this process plants make their own food and produce oxygen along with it. Plants also consume oxygen for respiration, but they produce more of it than they consume. That is why we say plants produce oxygen.
Animals cannot prepare their own food, so they depend on plants for food. Thus, animals cannot live without plants.

The balance of oxygen and carbon dioxide in the atmosphere is maintained through respiration in plants and animals and by photosynthesis in plants.
The CO2 produced during respiration of plants and animals is consumed during photosynthesis by plants.

 While the oxygen produced during photosynthesis by plants is consumed in respiration by plants and animals.
 This shows the interdependence of plants & animals.

OTHER IMPORTANT USES OF AIR

1.     Wind mill : Moving air is called wind. Wind makes the windmill rotate.
    The wind mill is used to draw water from tubewells and to run flour mills. They are also used to generate electricity.

2.    Air helps in sailing yachts, gliders, parachutes and aeroplanes.

3.    Birds, bats and insects can fly due to the presence of air.

4.    Air also helps in dispersal of seeds and pollens of flowers and several plants.

5.    Air plays an important role in water cycle.

KEY WORDS

1.    Atmosphere : The envelope of air that surrounds the earth is known as atmosphere.
2.    Carbon Dioxide : Carbon dioxide is a gas produced during respiration. It is also produced on burning of organic substances. It is used by plants for photosynthesis.
3.    Composition of Air : Air is a mixture of nitrogen, oxygen, carbon dioxide, water vapour and a few other gases.
4.    Oxygen : Oxygen supports burning and is necessary for living organisms.
5.    Nitrogen : It is the major portion of our atmosphere
6.    Smoke : These are the dark-coloured mixture of gases produced due to the burning of anything
7.    Windwill : windmill is a huge apparatus which is rotated by wind. It is used to draw water from tube wells and to run flour mills.