Which term best describes the ability of living organisms to respond to sensory input?

Which term best describes the ability of living organisms to respond to sensory input?

• A. Photosynthesis
• B. Metabolism
• C. Irritability
• D. Homeostasis

Answer: (C)

Responding to sensory input is a basic characteristic of life called irritability. It means organisms can detect changes in their environment and produce a response appropriate to that change. For example, a plant may bend toward light, or an animal may withdraw from something hot, illustrating how organisms sense stimuli and react. This idea is distinct from photosynthesis, which is about converting light energy into chemical energy; from metabolism, which encompasses all the chemical processes in an organism; and from homeostasis, which is about maintaining stable internal conditions. Irritability specifically describes the ability to sense and respond to external cues.

Responding to sensory input is a basic characteristic of life called irritability. It means organisms can detect changes in their environment and produce a response appropriate to that change. For example, a plant may bend toward light, or an animal may withdraw from something hot, illustrating how organisms sense stimuli and react. This idea is distinct from photosynthesis, which is about converting light energy into chemical energy; from metabolism, which encompasses all the chemical processes in an organism; and from homeostasis, which is about maintaining stable internal conditions. Irritability specifically describes the ability to sense and respond to external cues.