What is the growth response of plants to directional stimuli called?

The term for the growth response of plants to directional stimuli is known as tropism. This is a general term that encompasses various specific types of growth responses to different environmental stimuli. Tropisms are categorized based on the nature of the stimulus, such as light, gravity, or touch.

In the context of plant behavior, when a plant grows towards a stimulus, this is referred to as positive tropism, and when it grows away from a stimulus, it is known as negative tropism. The specific types include:

• Phototropism, which is the growth response to light.

• Gravitropism, which is the response to gravity.

• Thigmotropism, which is the response to touch or physical contact.

Since the question asks specifically about the general growth response to directional stimuli without providing a specific type of stimulus, the most accurate term is tropism, as it encompasses all directional growth responses in plants.