Genetic variation occurs.
Mutations are not copied over and over again.
Artificial Selection? I'm just guessing
They give us the energy we need to move and to speak and to live they do that for all the organisms on earth
Answer:
It controls the rate at which chyme enters the small intestine
Explanation:
Cephalic phase is one of the phase of gastric secretion (other two are gastric phase and intestinal phase) that begins even before food enters the oral cavity. Thinking of food stimulates the release of gastric juice via parasympathetic nervous system). Food that enters the stomach also stimulates the secretion of gastric juice by parietal cells. Partially digested food directly activates G cells (Enteroendocrine cells) to secrete gastrin which also stimulates the release of gastric juice.