What process occurs when chromosomes are in the tetrad?
A. The chromosomes exchange portions of their
DNA crossing over genetic information.
B. The chromosomes are doubled in preparation
for fertilization.
C. All the genetic information is segregated, so it
does not mix in the chromosomes.

The large increase in atmospheric carbon dioxide in the last 50 years most likely comes from a. an increase in cellular respiration b. increased decomposition by bacteria c. an increase in the burning of fossil fuels d. an increase in photosynthesis

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).

Jason, a dog breeder, decides to mate a poodle with a golden labrador retriever. he wants to get puppies with the curly hair of the poodle and the color of the labrador. what concept is shown in this example? question 6 options: artificial selection adaptation evolution natural selection