In what ways are the thigh muscles and arm muscles similar? (i) They create movement by contracting and relaxing. (ii) They work in pairs. (iii) they are attached to the bones A) Only (i) and (iii) C) Only (i) and (ii) B) Only (ii) and (iii) D) (i), (ii) and (iii)

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explanation:

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many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.