Organisms that only eat plants are known as herbivores. Organisms which eat both plants and animals are omnivores. Next, consumers feed upon consumers this is known as a food chain. Organisms that only eat other animals are called carnivores. An example of a simple food chain is an insect that is eaten by a fish which is then eaten by a bear.
Consumers feed on other consumers until the uneaten predator dies.
They recycle water, nutrients, and energy back into the ecosystem. Doing this creates nutrient-rich soil that the plants use to repeat the cycle. The human body is composed of eight body systems. All of our life activities are triggered by our nervous system, with the central controls in our brain. Our nervous system allows us to respond to stimuli.