Gas exchange is more difficult for aquatic animals with gills than for terrestrial animals with lungs because _____
A) water is less dense than air
B) water contains much less oxygen per unit volume than air
C) gills have less surface area than lungs
D) gills allow only unidirectional transport
E) gills collapse in air
Answer: B
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Indicate whether the statement is true or false.
Erasmus Darwin, in his discussion of evolutionary possibilities, included all of the following EXCEPT
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________ is a polymer of glucose.
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