MICROANATOMY

Detailed explanation-1: -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-2: -The door to your house is like the gated channel of a cell membrane. The cell membrane protects the content of the cell just like the walls of the house and the gated channel works like a door that remains closed but can open up when certain substances need to be allowed inside the cell.

Detailed explanation-3: -Cell wall is the outermost boundary in plant cell whereas plasma membrane or cell membrane is the outermost boundary in animal cells. In a plant cell, cell membrane is found in the inner side of the cell wall. Occurrence: Cell membrane is present in all cells.