Which of the following is true of a cell membrane?
A. They allow all substances to pass
B. It's selectively permeable
C. Cell membranes surround plant, animal, and bacteria cells
D. It's a bi-layer composed of phospholipids and proteins
Ans:
B. It's selectively permeable
C. Cell membranes surround plant, animal, and bacteria cells
D. It's a bi-layer composed of phospholipids and proteins
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In DNA the pyrimidines are
a. thymine and cytosine. b. adenine and cytosine. c. adenine and guanine. d. thymine and adenine. e. guanine and thymine.
When a photosystem absorbs light, _____
a. sugar phosphates are produced c. RuBP accepts electrons b. electrons are transferred to ATP d. electrons are ejected from its special pair
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A) cerebellum B) thalamus C) amygdala D) hypothalamus E) reticular formation
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the wet conditions of the digestive system to release the drug to the body. A) ionic bonds; salt B) hydrogen bonds; base C) ionic bonds; acid D) covalent bonds; salt