Definition: This is the actions of organisms in response to stimuli.

The definition this is the action of organisms in response to stimuli is known as homeostasis.

Explanation:

The process by which organisms react to stimuli that keep the conditions in their body suitable for life is called homeostasis. They are the organisms that maintain the stable internal environment. Stimulus is the environmental change that directly influences the activity of a living organism.

A stimulus is a change in the physical or chemical structure of an organism's internal or external environment. The ability to respond to external stimuli is called sensitivity. The plant bend towards the sun is an example of response to a stimuli in an organism.