NEET BIOLOGY

Detailed explanation-1: -By acting as a gatekeeper, the plasma membrane protects the cell from its surroundings and keeps important molecules from leaving the cell, so that the correct balance of molecules is maintained.

Detailed explanation-2: -The cell’s outer membrane acts as a gate, preventing intruders from invading the cell. But viruses, like HIV, manage to sneak through the cell’s protective barrier.

Detailed explanation-3: -A: Facilitated diffusion works like a gate, the cell membrane acts as the gate keeper. When something that wants to enter a cell reaches a cell membrane and it can not enter via diffusion, a gate will open and allow the molecule to enter. The proteins that sit on the outside of the cell membranes act as the gates.

Detailed explanation-4: -By allowing some materials but not others to enter the cell, the cell membrane acts as a gatekeeper. The cell membrane also provides structural support to the cytoplasm, recognizes foreign material, and communicates with other cells, all of which contribute to maintaining homeostasis.