Final answer:
The statement that Spirochetes are common inhabitants of the human colon is false; they are spiral-shaped, not rods, and are not prevalent in the human gut like E. coli.
Step-by-step explanation:
The statement that Spirochetes are gram-negative rods that are common inhabitants of the human colon is false. While spirochetes do have a spiral shape and are gram-negative-like, they are not classified as rods, nor are they common inhabitants of the human colon. The gram-negative rod Escherichia coli (E. coli), however, is a prevalent bacterium in the human gut. Most E. coli strains are helpful commensal bacteria, but some can be pathogenic, causing diarrheal diseases. In contrast, spirochetes are known for their spiral-shaped cells and are typically free-living anaerobes, with some being pathogenic, causing diseases such as syphilis and Lyme disease. The correct answer to the question would be B) False.