Question

All living things respond to external stimuli

Answer 1

No people in coma stage will not although they are living They'll not eespond

Answer 2

Response to stimuli is an important characteristic of life. Anything that causes a living organism to react is called a stimulus. Stimuli can be external or internal.
For an organism to be considered alive, it has to have some level of response to a stimulus.
When a stimulus happens, it is interpreted by three components. The receptor is what first notices the stimulus happening. The receptor then sends a signal to the control center, which is the nervous system. The nervous system makes a decision and sends a signal to an effector.