Which is an explanation of the importance of carbonates for marine life? Select all that apply.

Carbonates form part of the skeletal structure of corals, sea urchins, and other aquatic life.
Carbonates supply calcium carbonate, a critical building block for the shells of oysters and clams.
Carbonates decrease the pH of the ocean, which improves the health of marine organisms.
Carbonates increase the ocean’s solubility so that marine organisms have adequate oxygen for survival.

Genetic diversity is the variation in the genes of an entire species. each circle represents a population of a particular species in different habitats. select the population with maximum genetic diversity

Human genes only differ by less than percent. a. 1 b. 6 c. 11 d. 16

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).