Answer:
nucleus and we need dna so we can figure out people in our past
Explanation:
The rapid depolarization phase
of myocardial contractile cells is due to the Na+ ions. Sodium ions are essential
for regulation of blood and body fluids, communication of nerve impulses, heart
activity, and metabolic purposes. Physiologically, it survives as an ion in the
body. Sodium is needed by
animals but is not needed by plants. The human prerequisite for sodium<span> must be less
than 500 mg per day. </span>
<span>Muscle color is related to muscle specialization because it indicates whether muscles are used more for aerobic or anaerobic metabolism. Aerobically respiring muscles that do work over a long period of time have more red oxidative fibers, while anaerobically respiring muscles that do work in bursts have more white glycolitic fibers.</span>
