Question

Which of the following act as an internal stimuli for generation of response?

• A. Light
• B. Smell
• C. Thyroxine
• D. Sound

Answer 1

Answer: (C)

Thyroxine

• The stimulus(singular) is any change in the organism's internal or external environment that causes the organism to react. It is of two types external and internal.
• External stimulus is the stimulus that comes outside of the organism. For example, Light stimulus, heat stimulus, chemical stimulus, sound stimulus, etc.
• The internal stimulus is the stimulus that comes from inside an organism. Humoral stimuli(release of hormones like thyroxine) and neural stimuli etc
• Hence thyroxine act as an internal stimulus for the generation of a response.
• So, the correct answer is 'Thyroxine'.