They both hunt for food and will ruthlessly kill you before you can cry, "MAMA!"
Because the molecules that are being transported is moving against its concentration. gradient. in other words, its moving from where it's low in concentration to where it's high in concentration.
Let's just say that everyvyear, many people either get the vaccination, or the flu. These people are left immune to the strain of flu that they were vaccinated/infected with so the number of people who can get and pass on that form of flu (think of these people as that flu strain's "habitat") is reduced. If some of that flu mutates sufficiently that the immune systems of those previously infected vaccinated people no longer recognize it, then it's habitat is expanded back to the original size again.
Hope this helped :)
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It is hard to understand this question but ill give you my best answer. The hearts level of organisation to cells is immense, the heart pumps blood to every cell in the body (so they can respire) through a system of Arteries, veins and capillaries. The blood is pushed by the force of the heart through the arteries, the main (and largest) tubes for transportation to segments of the body further away from the heart. This goes into a smaller system of veins that brake off into a tree kind of pattern to reach every cell. These later brake off into the capillaries that have walls only 1 cell thick. This is how blood is transported to each cell that requires energy and oxygen to respire.
