Slides containing bacteria are stained with crystal violet and iodine, destained with alcohol, and counterstained with safranin. Under the mircoscope, the bacteria appear a bluish-purple color. Which class of bacteria are on the slide?
Gram-negative bacteria
Helicobacter
Gram-positive bacteria
Mycobacteria
What is the shape of a streptobacillus bacterium?
Round
Non-rigid helix
Rigid helix
Rod-shaped