Final answer:
TRUE: The pupils of the human eye dilating in a dark environment indicates that the eye is responding to its environment, a sign of life. The pupillary reflex involves both parasympathetic and sympathetic nervous systems to maintain homeostasis.
Step-by-step explanation:
TRUE: The statement that the pupils of the human eye dilate in a dark environment as a characteristic of life - RESPONDS TO THE ENVIRONMENT - is a true characteristic. This is known as the pupillary reflex, a homeostatic mechanism. When light levels are low, the sympathetic nervous system causes the pupils to dilate, allowing more light to enter the eye. Conversely, in bright light, the parasympathetic system induces constriction of the pupil via the oculomotor nerve to limit light entry and protect the retina. This reflex is evidence of the eye's ability to respond to environmental changes, and is an important aspect of maintaining homeostasis in the body.