Which characteristic best describes a coccoid bacterium?

• A. It forms spores.
• B. It has a spherical shape.
• C. It grows better in an acidic environment.
• D. It does not absorb Gram's stain.

Answer: (B)

Coccoid describes the shape of the bacterium. The term refers to organisms that are round or spherical, so the best descriptor is a spherical shape. Spore formation isn’t tied to being coccoid—many cocci don’t form spores, and spore formers are often rod-shaped. Growth in acidic environments is a physiological trait, not a defining feature of the coccoid form, and Gram staining varies among cocci (some are Gram-positive, some Gram-negative), so the stain behavior doesn’t define coccoid.