<span>The answer is a certain required chemicals must be actively
transported. Blood brain barrier is a
selective membrane that separates blood circulating from the brain and the
fluid of extracellular in the central nervous system. This is also called a
filtering mechanism, the capillaries that carry blood to the brain and spinal
cord tissue blocking the path way of the certain substance.</span>
Answer:
The effect might be due to the gene expression.
Explanation:
The effect might be due to the variation in the gene expression in the organism. In this way, the variety of the genetic pool is likely to result in a diversity of the gene pool or genome. Because of the mutation and the environmental factors, there is likely to be a slight variation of the species. This results in a slight difference in the phenotypic expression.
Answer:
cells that should not invade other tissues do invade other tissues
Explanation:
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.
The answer syncline. hope this helps