5.3a Dynamic equilibrium results from detection of and response to stimuli. Organisms

detect and respond to change in a variety of ways both at the cellular level and at the

organismal level.

5.3b Feedback mechanisms have evolved that maintain homeostasis. Examples include

the changes in heart rate or respiratory rate in response to increased activity in muscle

cells, the maintenance of blood sugar levels by insulin from the pancreas, and the

changes in openings in the leaves of plants by guard cells to regulate water loss and gas