Describe how a bird's skeletal system, respiratory system, and circulatory system all work together and enable a bird to fly.

Aneuron is stimulated with an electric pulse. the action potential is detected at a point 3.70 cm down the axon 0.0052 s later. when the action potential is detected 7.20 cm from the point of stimulation, the time required is 0.0063 s. what is the speed of the electric pulse along the axon? (why are two measurements needed instead of only one? )

What percentage of light hits earth's surface directly?

Apuppy’s tendency to chew is inherited through which of the following? a. through learned behavior b. through genes c. through seasonal cycles d. through hibernation