Why are toxins more concentrated in sediments than in the overlying water column?
What will be an ideal response?
Many toxic substances such as heavy metals and synthetic organic compounds have high affinities for suspended particles or floating phytoplankton cells. As a result, when these particles settle, or when the phytoplankton die or are eaten by benthic organisms, the pollutants ultimately find their way into the sediment sink where they remain until disturbed.
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Which is NOT one of the four extraembryonic
membranes of the amniote egg? a. albumin b. amnion c. chorion d. allantois e. yolk sac
People homozygous for a specific high-risk allele of thefto gene ____
a. tend to overeat b. store more fat c. are naturally heavier d. are always overweight e. cannot undergo gastric bypass surgery
Nitrogen __________ by bacteria in root __________ gives a plant extra nitrogen. Fill in the blank(s) with the appropriate word(s)
The breast muscle of turkeys and chickens is usually referred to as light meat, whereas that of wild ducks and geese is described as dark meat. How might this be explained?
A. The muscles of ducks and geese do not contain myosins. B. Turkeys and chickens do not fly for sustained periods, whereas wild ducks and geese do. C. The darker body color of ducks and geese provides protective camouflage against predators. D. Turkeys and chickens are not closely related to ducks and geese.