6. Which statements about the prokaryotic cell envelope is/are true?
a) It is a tightly bound three-layered structure.
b) The layers are glycocalyx, cell wall, and plasma membrane, in order from outside in.
c) Bacteria that take up Gram stain are called Gram-negative.
d) The glycocalyx, if thick and tough, is called the slime layer.
e) The cell wall gives the cell shape and structural support.
f) The plasma membrane is selectively permeable.
g) The three layers of the envelope function as separate, independent units.