by Anne StClair

Created on: April 05, 2007   Last Updated: May 04, 2007

Without plant life there would be no global food chain. Green plants take water, carbon dioxide and light, and through photosynthesis turn them into oxygen and a simple sugar called glucose. Glucose consists of carbon, hydrogen and oxygen, and forms the basis of carbon-based life forms (which is what all life forms on Earth are). Starch and cellulose, which form the structure of plants, are made from glucose, as is glycogen (which is the animal equivalent to starch in plants and which acts as a glucose storage system).

Every creature on Earth that cannot create its own food must ultimately consume something that can. In other words plant life, which creates its own food through photosynthesis, is at the bottom of every food chain. Everything else has to either eat the plant, or eat the animal that ate the plant, or eat the animal that ate the animal that ate the plant, or...

The plant eaters are herbivores, while those that eat animals are carnivores. Omnivores will eat a range of foods, but their existence too rests on the plants, because no animal can produce its own food out of light, water and air. And that is, as they say, 'the bottom line': no plants, no food chain, no life.

Learn more about this author, Anne StClair.
Click here to send this author comments or questions.