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33 votes
33 votes
How does a substance cross the cell membrane in diffusion?

a- flowing down the concentration gradient
b- binding to a carrier protein
c- going through a pump
d- going through a channel protein
(ck-12)

User Gustavo F
by
2.5k points

1 Answer

13 votes
13 votes

Answer:

A

Step-by-step explanation:

User Reimus Klinsman
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