ANATOMY

Detailed explanation-1: -It is true that a membrane which allows only certain substances to pass through, but does not allow others to pass through it is called a selectively permeable membrane. For example, the plasma membrane of eukaryotic cells.

Detailed explanation-2: -SELECTIVELY PERMEABLE means letting some but not all substances pass through. OSMOSIS is the process by oxygen molecules tend to move from an area of higher concentration to an area of lower concentration. The process by which water moves across a selectively permeable membrane is called DIFFUSION.

Detailed explanation-3: -The membrane is selectively permeable because substances do not cross it indiscriminately. Some molecules, such as hydrocarbons and oxygen can cross the membrane. Many large molecules (such as glucose and other sugars) cannot. Water can pass through between the lipids.

Detailed explanation-4: -The cell membrane is called selectively permeable as it only allows specific molecules to pass. Only specific molecules like water and gaseous molecules can pass through the cell membrane directly. It stops the flow of other molecules towards the two sides.

Detailed explanation-5: -A membrane that has selective permeability allows only substances meeting certain criteria to pass through it unaided. In the case of the cell membrane, only relatively small, nonpolar materials can move through the lipid bilayer at biologically relevant rates (remember, the lipid tails of the membrane are nonpolar).