What term describes a plant's growth response to environmental stimuli?

The correct term for describing a plant's growth response to environmental stimuli is tropism. This term encompasses various directional growth responses that plants exhibit in reaction to specific environmental factors, such as light, gravity, and touch. Tropisms are typically categorized based on the stimulus:

• Phototropism, which is a specific type of tropism, refers to a plant's growth response towards light. This phenomenon allows plants to maximize light absorption necessary for photosynthesis.

• Geotropism (or gravitropism) describes how plants respond to gravity, with roots showing positive geotropism as they grow downward, while stems exhibit negative geotropism by growing upward.

• Etiolation refers to a plant’s elongated growth pattern in the absence of sufficient light, helping it reach light sources quickly.

While phototropism and geotropism are specific examples of tropism, the broader term 'tropism' effectively captures the general concept of how plants adapt their growth based on various environmental cues. Therefore, the term 'tropism' accurately encompasses all these responses under a single umbrella concept.