Indicate the true statements and then correct the false statements so that they are true.
a. The Gram stain is a simple stain.
b. Simple stains reveal information about size, shape, and arrangement.
c. Bright field microscopy requires a stained sample.
d. Dark field microscopy requires a stained sample.
e. The acid-fast stain detects peptidoglycan in the cell walls of certain bacteria.
f. Gram-positive bacteria have a thin peptidoglycan layer in the cell wall.