Anything that has or once had all the characteristics of life.

The orderly structure shown by living things.

The process that results in mass being added to an organism; may include the formation of new cells and new structures.

The changes an organism undergoes in its lifetime before reaching its adult form.

The production of offspring

A group of organisms that can interbreed and produce fertile offspring.

Any change in an organism's internal or external environment causes the organism to react.

An organism's reaction to a stimulus.

The regulation of an organism's internal environment to maintain conditions needed for life.

The inherited characteristic of a species that develops over time in response to an environmental factor, enabling the species to survive.

A body of knowledge based on the study of nature.

A testable explanation of a situation.

An explanation of a natural phenomenon based on many observations and investigations over time.

Describes relationships under certain conditions in nature.

An assumption based on prior experience.

A process in which the procedures used during an experiment may be repeated and the results are evaluated by scientists who are in the same field or are conducting similar research.

A set of guidelines protects participants and the environment and reduces bias in experiments.