AP BIOLOGY

Detailed explanation-1: -Therefore, the correct answer is cell membrane. Cell membranes are found in all cells. It serves as the barrier that protects the cell from the external environment.

Detailed explanation-2: -All cells, however, have both a cell membrane to enclose the cell and cytoplasm, which is the watery substance that contains all of the contents of the cell.

Detailed explanation-3: -All cells have a plasma membrane, ribosomes, cytoplasm, and DNA. The plasma membrane, or cell membrane, is the phospholipid layer that surrounds the cell and protects it from the outside environment. Ribosomes are the non-membrane bound organelles where proteins are made, a process called protein synthesis.

Detailed explanation-4: -The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell.