Question

True or false ? Cell membranes are selectively permeable, allowing only some materials to cross the cell membrane. This

Answer 1

Answer:

True

Explanation:

Cell membranes are selectively permeable because of the structure of the phospholipid bilayer.

This bilayer only lets certain things in because it depends on the polarity, size,  and type of molecule.

For example, glucose molecules are too large to enter. But, carbon dioxide molecules can go in and out easily because of their small size.

Answer 2

Answer:

This statement is True

“One way that a cell maintains homeostasis is by controlling the movement of substances across the cell membrane. The lipid bilayer is selectively permeable to small, nonpolar substances. Proteins in the cell membrane include cell-surface markers, receptor proteins, enzymes, and transport proteins.”