Which statement about Gram-positive bacteria is true?
A) They stain blue to purple and have walls with a relatively high concentration of peptidoglycan.
B) They stain pink to red and have relatively little peptidoglycan in their cell walls.
C) They weigh more than a gram.
D) They were discovered before Gram-negative bacteria.
E) They have no peptidoglycan in their cell walls.

Question

Quizplus · Accepted Answer

Gram-positive bacteria stain blue to purple due to their thick peptidoglycan layer, which makes up a significant portion of their cell wall. Gram-negative bacteria stain pink to red and have thinner peptidoglycan layers. Gram-positive bacteria were discovered before Gram-negative bacteria, and there is no evidence to suggest that they weigh more than a gram. Finally, some bacteria have may have little to no peptidoglycan, but these are not classified as Gram-positive or Gram-negative.

Which Statement About Gram-Positive Bacteria Is True