Answer: C. Germ Theory
Explanation: Germ Theory states that most diseases are caused by the presence micro-organisms within the body.
Presently, it is the accepted scientific theory for many diseases.
Explanation:
A slow, continuous process is defined as gradualism that occurs at slow rate but at a steady pace.
For example, stripes of a tiger develop slowly and at a steady pace so that they can hide in tall grass represents gradualism.
Whereas punctuated equilibrium is a process in which there is sudden and frequent changes that results in the formation of new species.
For example, species living in a sea for thousand of years breed and die over there and suddenly when there is change in sea level than animals must adapt represents punctuated equilibrium.
NAD is the electron carrier which is used in redox reactions in cellular respiration
Parietal cells within the stomach lining secrete hydrochloric acid that lowers the pH of the stomach. A low pH (1.5 to 2) activates pepsin. Acetylcholine, gastrin, and histamine stimulate the proton pump in parietal cells to release hydrogen ions and decrease pH.