Answer:The cell membrane functions as a barrier that makes it possible for the cytoplasm to maintain a different composition from the material surrounding the cell. The unit membrane is freely permeable to water molecules but very impermeable to ions and charged molecules. It is permeable to small molecules in inverse proportion to their size but in direct proportion to their lipid solubility.
Explanation:
it allows for nutrients to come into the cell using passive tranport aka moving anything on a gradient without the use of energy (ATP).
Sensory, interneuron, motor
