In order for Tiktaalik to be considered a transitional fossil, when does it need to have appeared in the fossil record? a) after amphibians
b) between fish and amphibians
c) before fish
d) at the same time as amphibians
e) before fish and amphibians

PLZ ANSWER URGENT ASAP

Which of the following is not a benefit of green revolution? a) new crop varieties b) increased crop yields c) cost effective d) new crops may require larger amonts of water than the previous ones.

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).

Which of the following is caused by reproductive isolation within a species? a. a decrease in gene flow b. an increase in genetic flow c. a decrease in genetic drift d. an increase in gene flow