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

Question

Quizplus · Accepted Answer

Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, which makes them stain blue to purple when the Gram stain is applied. Gram-negative bacteria, on the other hand, have a thinner layer of peptidoglycan and an outer membrane that contains lipopolysaccharides, which makes them stain pink to red. Choice B, D, and E are incorrect statements about bacteria. Choice C is incorrect because the Gram stain has nothing to do with the weight of the bacteria.

Which Statement About Bacteria Is True