When we breathe, we take in oxygen and give out carbon dioxide and water vapour. Nature has a wonderful way to maintain equilibrium to make sure there is always enough oxygen to keep us alive. This is how plants help us through a process called photosynthesis.
Photosynthesis is the process by which plants use up carbon dioxide from the surrounding air and water in the presence of sunlight, to create glucose, which they use to live and grow. This process is most important for the survival of all the animals on earth because plants give out oxygen in the process, and the glucose and animals use sugars that are created, as food. As a result of this, plants are called autotrophs, or organisms that produce their own food.
Did you know? Plants appeared on earth millions of years before animals did. If plants had not released oxygen by photosynthesis, animals that breathed oxygen would not have evolved and we would probably not be alive!