According to the cross-linkage theory of aging, bonds between protein fibers in connective tissue can lead to reduced production of many hormones, especially estrogen loss of flexibility in the skin and clogging of arteries tightening of the skin and strengthening of the kidneys increased flexibility and strengthening of the bones

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? )

The structure that houses the cells genetic information.

The ultimate purpose of respiration: a. inhale 02 and exhale co2 b. place oxygen in the lungs c. place oxygen in the blood d. deliver oxygen to every blood cell