Which of the following is an example of active transport?
A. diffusion
B. moving molecules from an area of high to low
concentration
C. moving molecules against a concentration
gradient
D. moving molecules with the concentration
gradient

the real answer is b. scintillation counter

scientists have discovered that hiv does not cause aids by the virus's direct effect on the host's immune cells, but rather through the cells' lethal influence on one another. researchers from the gladstone institutes have revealed that hiv does not cause aids by the virus's

producers: apple trees, potatoes, carrots, grains, acorns, cabbage, grass, corn, lettuce

consumers: deer, mice, rabbits, chickens, squirrels, horses, worms, cows

predators: eagles, frogs, wolves, owls