Which of the following correctly lists the levels of compaction in eukaryotes from naked dna to the most compact?
a. solenoid, nucleosome, looped chromatin (300-nm fiber), metaphase chromosome
b. solenoid, metaphase chromosome, nucleosome, looped chromatin (300-nm fiber)
c. metaphase chromosome, nucleosome, solenoid, looped chromatin (300-nm fiber)
d. nucleosome, solenoid, looped chromatin (300-nm fiber), metaphase chromosome
e. nucleosome, looped chromatin (300-nm fiber), metaphase chromosome, solenoid

Which statement describes a way in which the digestive and excretory systems work together? a. the nephrons absorb nutrients from food going to the large intestine. b. the excretory system balances blood gases in the small intestine. c. the intestinal villi filter blood and send wastes to the bladder. d. the excretory system balances the salts and water obtained from digested food

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).

_tissues respond quickly to outside stimuli a) epithelia b)nervous c)muscular d)muscular and nervous