Living beings take in Oxygen and throw out Carbon Dioxide the plants use this same Carbon Dioxide to make food and throw out Oxygen.

Plants take the Carbon Dioxide from the air and water and minerals from the soil to make food, which animals eat. Plants and animals use energy for growth the bodies of plants and animals comes from soil, air and water.

Nature has the right amount of plants, herbivores and carnivores .If any one these elements vanish from the earth the whole balance will be disturbed for example: