Gram-positive (+) and gram-negative (–) bacteria are characterized by differences in:
A) the cell wall: gram+ have peptidoglycan, gram– have pseudo-peptidoglycan.
B) the plasma membrane: gram+ have ester-linked lipids, gram– have ether-linked lipids.
C) the cell wall: gram+ have a thick layer of peptidoglycan and gram– have an outer membrane.
D) chromosomal structure: gram+ have circular chromosomes, gram– have linear chromosomes.