2.5

• The cell membrane is selectively permeable, allowing small non-polar molecules to pass freely while restricting the movement of large polar molecules and ions.
• The cell wall serves as a structural boundary, protecting and maintaining the shape of the cell.
• Plasmodesmata are small holes between plant cells that allow the transfer of nutrients, waste, and ions.
• Hydrophilic substances move through transport proteins, including channel proteins and carrier proteins.
• The cell wall prevents cellular rupture under high internal water pressure and helps plants withstand gravity.