Question

the cell membrane, also known as the plasma membrane, separates the inside of the cell from the outside environment. it is a semipermeable barrier. the latin prefix semi- means half, and permeable means having pores or openings that substances can pass through. what is the significance of a semipermeable cell membrane? the cell membrane does not allow any substances to enter or leave the cell. the cell membrane only allows certain substances to enter or leave the cell. the cell membrane allows all substances to enter or leave the cell.

Explanation:

To determine the significance of a semipermeable cell membrane, we analyze the meaning of "semi - permeable". The prefix "semi - " means half and "permeable" means having pores for substances to pass through. So a semipermeable membrane should allow only some (certain) substances to pass through, not all (which would be fully permeable) and not none (which would be impermeable).

• The first option says no substances can enter or leave, which is incorrect as the cell needs to exchange substances.
• The third option says all substances can enter or leave, which is incorrect because the cell needs to regulate what comes in and out (e.g., allowing nutrients in and waste out while blocking harmful substances).
• The second option, "The cell membrane only allows certain substances to enter or leave the cell", matches the definition of semipermeable.

Answer:

The cell membrane only allows certain substances to enter or leave the cell.