What is the term used to describe growth in response to a stimulus?

The term that describes growth in response to a stimulus is tropism. Tropisms are directional growth movements that occur as a reaction to external stimuli. For instance, plants may exhibit phototropism, where they grow towards light, or gravitropism, where they respond to gravity by directing their roots downwards and their stems upwards. This ability to sense and respond to stimuli is critical for plants as it helps them optimize their growth conditions and survive in their environments.

In contrast, homeostasis refers to the maintenance of stable internal conditions within an organism, adaptation describes the process through which species evolve features that enhance their survival in specific environments, and metabolism encompasses all the biochemical reactions that occur within organisms to maintain life. None of these terms capture the specific phenomenon of growth directed by an outside stimulus as accurately as tropism does.