The Gram method is useful for classifying all bacteria that
A) have two plasma membranes.
B) have cell walls.
C) have cell walls with at least some peptidoglycan.
D) are prokaryotic.
E) form endospores.

Question

Quizplus · Accepted Answer

The Gram method is based on differences in bacterial cell wall composition, specifically the amount and structure of peptidoglycan. Therefore, it is useful for classifying bacteria that have cell walls with at least some peptidoglycan, as in choice C. Bacteria with two plasma membranes (choice A) are very rare and not typically classified based on the Gram method. While all bacteria are prokaryotic (choice D), this is not specific enough to be the best answer. Formation of endospores (choice E) is not related to Gram classification.

The Gram Method Is Useful for Classifying All Bacteria That