Answer:
The correct answer is option b, that is, enteroendocrine cells.
Explanation:
The specialized cells of the pancreas and the gastrointestinal tract exhibiting endocrine function are termed as enteroendocrine cells. These cells generate gastrointestinal peptides or hormones in response to a distinct kind of stimuli and discharge them into the bloodstream for the systemic effect. These are the most varied endocrine cells found within the body.
The intestinal enteroendocrine cells produce somatostatin, cholecystokinin, motilin, enteroglucagon, and neurotensin hormones. The G cells present within the intestine produce gastrin. In the gastric glands, the gastric enteroendocrine cells are present, which produce histamine, and others like cholecystokinin, alpha and gamma-endorphin, somatostatin, and others.
In the islets of Langerhans, the pancreatic enteroendocrine cells are present, which produce hormones like ghrelin, amylin, somatostatin, and pancreatic polypeptide.
Answer: Natural selection can be defined as the differential survival and reproduction of members of the population of a species that have suitable traits to survive in a population of species.
Explanation:
The punctuated changes in the population of species have been found inordinately faster in the geological time scale, but changes per-generation have been relatively slow. Also, the rate of evolution in such a population is also slow. The punctuated changes in the population are because of evolution but the per-generation changes are the outcomes of the natural selection, in which only the beneficial traits are passed from one generation to another.
<span>Simply because cells need both these types of molecules for proper function.</span>
