"Energy cannot be created or destroyed." Explain why this is true in relation to photosynthesis and respiration.

Blood has traveled from the heart to the toes. which describes the next step of the circulation process?

Which direction does the energy flow in this energy pyramid ?

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.