Answer:
Active transport: movement against a gradient To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the proper concentrations of ions and molecules in living cells.
Parietal cells produce gastric acid (hydrochloric acid) in response to histamine (via H2 receptors), acetylcholine (M3 receptors) and gastrin (gastrin receptors). Parietal cells contain an extensive secretory network (called canaliculi) from which the HCl is secreted by active transport into the stomach.
All living things grow, also, all living things can adapt and every living thing is made up of cells.
Answer:
The answer is the integumentary system. Hope that helps! :)
