Why do cells need a hydrophilic part to the plasma membrane

Vegetation that grows along the floors of tropical and temperate forests is called undergrowth. how is the undergrowth of a tropical rain forest most likely to differ from the undergrowth of a temperate forest? a. a tropical rain forest's undergrowth most likely experiences periods of dormancy during colder weather. b. a tropical rain forest's undergrowth most likely experiences periods of dormancy during rainy weather. c. the undergrowth of a tropical rain forest most likely requires less sunlight. d. the undergrowth of a tropical rain forest most likely requires more sunlight.

The kidney filters potentially toxic substances in the blood, and thus “clears” the blood of those substances. this clearance function is dependent upon and proportional to the diffusion gradient of the substance across filtering capillaries, i.e. if the concentration of the substance is doubled, twice as much will be cleared from each ml of blood that is filtered. suppose that the body produces a constant amount of a substance x per unit of time. the kidneys eliminate substance x at a rate directly proportional to the concentration of the substance and the volume of blood cleared each minute (c): elimination = c × [x], where [x] is the steady-state concentration of substance x. imagine an individual with an initial concentration of x equal to [x]0 who develops kidney disease. her baseline clearance c0 drops to one half of the original (½c0). what is the new steady state concentration of x? (for simplicity, assume that substance x is 100% filtered by the kidney).

(6.02 mc)what affect do marine protected areas have on environmental quality? they increase environmental quality by preventing resource overuse. they increase environmental quality by adding new species. they decrease environmental quality by removing all human activity. they decrease environmental quality by adding recycling facilities.