A food web can be described as the food relationship among all organisms that share the same environment. A food chain is a chain of eating and being eaten that connects large and carnivorous animals to their ultimate plant food. A food web is a grouping of interrelated food chains. In a food chain, matter differs from energy in that the matter can be recycled. The transfer of food from animal to animal is called the food cycle.
Carbon dioxide is released to the atmosphere by all organisms.
Animals high on the food chain are both larger and rarer than animals lower down. This is referred to as the Pyramid of Numbers or Eltonian Pyramid. This model has an order of magnitude of 10. A niche is the function of an organism in an ecosystem. It relates to what it uses as food and what uses it as food.