Gram-negative rods
A) are all closely related.
B) include Escherichia coli as well as many human pathogens.
C) can reproduce only within the cells of other organisms.
D) all possess structures called axial filaments.
E) include the important genera Bacillus and Clostridium.

Question

Quizplus · Accepted Answer

Gram-negative rods are a diverse group of bacteria that include many human pathogens, such as E. coli, Salmonella, and Shigella. Therefore, choice B is the best choice because it correctly identifies an important subset of gram-negative rods. Choices A, C, and D are incorrect because gram-negative rods are not all closely related, do not all reproduce exclusively within other cells, and do not all possess axial filaments. Choice E is also incorrect because Bacillus and Clostridium are actually gram-positive rods.

Gram-Negative Rods