These molecules need to pass through specific proteins or transmembrane proteins embedded in the cell membrane. A specific type of an integral membrane protein.
Erosion is the breakdown of anything. Like for example rock erosion is when the water keeps hitting the rock over and over until then the rock sarts to breakdown.
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The answer is number two extinction happened, this was the time dinosaurs went extinct ebcause lack of sun because oh how much dirt was blown into the earth atmosphere becuase of the asteriod, third option is talking about big bang theroy so that dosnt apply!
Explanation:
