The cell membrane that surrounds all cells is said to be semipermeable. What does this mean?
A) Only particles of a substance that are small enough can pass through the cell membrane.
B) The cell membrane consists of two layers of lipids with proteins that are either embedded in these layers or on the surface.
C) The cell membrane always uses energy to transport particles of substances into and out of the cell.
D) Only certain substances can pass through the cell membrane.
Ans: D) Only certain substances can pass through the cell membrane.
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