What functions does the muscular system perform?
it provides stability, movement, and posture.
it generates and conducts electrical signals.
it produces melanin, which protects from the sun.
it produces oil, which protects from foreign invasion.

The current thought on the structure of the cell membrane is: a. a static phosphate sandwich of lipids b. a fluid-mosaic of phospholipids and proteins c. a bilayer of proteins with static lipid molecules d. an impermeable bilayer of protein molecules e. a static and permeable phospholipid single layer