The keystone species is the one at the bottom of the pyramid, if we look at it like a pyramid. If the grass dies, then the deer cannot get food and die, and the predator cannot eat and dies, and the whole ecosystem can fall apart.
Demultiplexor is your answer.. hope this helps.
Examples of active transport include the uptake of glucose in the intestines in humans and the uptake of mineral ions into root hair cells of plants.
Mice that are injected with the living R strain survive.
