Human organisms have interacting systems. Internal and external cues influence behavior. Some living organisms are so small we can only see them through a microscope. Life Cycles Of Organisms Plants and animals have life cycles that include birth, growth, reproduction, and death. Some characteristics are inherited in various combinations from parents.
All organisms cause changes in their environments.
A population consists of all organisms living together at a given place and time. An ecosystem is composed of all populations of organisms living together and the physical factors with which they interact. Populations of organisms can be categorized as producers, consumers, decomposers, etc. Humans can pollute ecosystems, but this can be prevented or resolved. These grade level performance standards are listed developmentally.