Which statement comparing examples of renewable and nonrenewable resources is true? a. solar energy is a renewable resource because it can't be used up, but oil is a nonrenewable resource because it will eventually run out. b. both solar energy and oil are renewable resources because they will never run out. c. solar energy is a nonrenewable resource because it can't be used up, but oil is a renewable resource because it will eventually run out. d. both solar energy and oil are nonrenewable resources because they will eventually run out.

In a classic experiment using pea shape, mendel conducted two separate genetic crosses. in the first cross the parent plants were “true breeding” for pea shape; one had round peas ( r )and the other had wrinkled (r). the first cross produced a filial 1 generation of all round peas. in the second cross, mendel bred plants from the filial 1 generation. this cross produced different results. out of approximately 1000 plants, about 75% were round and 25% were wrinkled.

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).

Tropical rain forests support more species per unit area than any other terrestrial ecosystem. what is one way rain forests are important to the health of the biosphere?