Question

the cell membrane is important for all cells because...
it aids in the manufacturing of proteins using ribosomes.
it holds all of the genetic materials for the cell.
it holds water, providing structure and support.
it controls what moves in and out of the cell, as well as provides a layer of protection

Explanation:

1. Analyze the first option: Protein synthesis with ribosomes occurs in the cytoplasm (or rough ER), not the cell membrane. So this is incorrect.
2. Analyze the second option: Genetic material (DNA) is held in the nucleus (or nucleoid in prokaryotes), not the cell membrane. So this is incorrect.
3. Analyze the third option: The vacuole (in plant cells) or cytoplasm's water content provides structure, and the cell wall (in plants/fungi) provides support. The cell membrane doesn't hold water for structure/support. So this is incorrect.
4. Analyze the fourth option: The cell membrane is a selectively permeable barrier that controls the movement of substances in and out of the cell and also provides a protective layer around the cell. This matches the function of the cell membrane.

Answer:

The correct option is: it controls what moves in and out of the cell, as well as provides a layer of protection.