Question

External stimulus comes from

• A. Outside of an organism
• B. Inside of an organism
• C. Skin
• D. None of the above

Answer 1

The correct option is A Outside of an organism

• In physiology, a stimulus is a detectable change in the internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity. When a stimulus is applied to a sensory receptor, it normally elicits or influences a reflex. Hence, External stimulus comes from

Outside of an organism.

So, the correct answer is 'Outside of an organism'.