AP BIOLOGY

Detailed explanation-1: -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-2: -The cell wall is freely permeable as it allows water and nutrients freely exchanged between the cells and outer environment.

Detailed explanation-3: -Cell membrane or plasma membrane is described as a selectively permeable membrane.

Detailed explanation-4: -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-5: -Cell membranes are selectively permeable, so only certain substances can passively diffuse directly across the membrane. These substances include small, nonpolar molecules such as carbon dioxide and molecular oxygen.