it is the cell wall ! :)
The cell membrane. It is described as semipermeable
The cell membrane, which is a lipid bilayer, controls the movement of substances in and out of the cell through processes like diffusion, osmosis, and active transport. It acts as a selective barrier, allowing some substances to pass through while blocking others.
Cell membrane
The cell membrane is the part of plant cells that regulates the movement of substances into and out of the cell. It acts as a barrier, allowing only specific molecules to pass through via various transport processes such as diffusion, osmosis, and active transport.
The cell membrane is reposnible for allowing what substances can enter and leave a cell, this happens by different methods of transport for instance "active transport" in plants. The phospholipid bilayer containing cholesterol, proteins and carbohydrates, also helps in allowing which substances to pass.
The cell membrane controls what substances enter or leave the cell. It is a selectively permeable barrier that allows certain molecules to pass through while blocking others. This regulation helps maintain the internal environment of the cell.
The plasma membrane of a cell plays a role in diffusion.
The Nucleus
I think you are talking about the nucleus, which is the "brain" of the cell. It controls everything that cell does.
The nucleus is what controls the cell.
nucleus
the nucleus.