Which term describes bacteria shaped like a corkscrew?

Which term describes bacteria shaped like a corkscrew?

• A. Spirilla
• B. Cocci
• C. Bacilli
• D. Protozoa

Answer: (A)

Bacteria come in a few basic shapes, and a corkscrew-like form is described as spiral. The term for these corkscrew-shaped bacteria is spirilla. They have rigid, helical bodies and move by twisting, with classic examples in the genus Spirillum. By contrast, cocci are spherical, bacilli are rod-shaped, and protozoa are not bacteria at all (they’re a different single-celled organism). So spirilla best matches the corkscrew description, capturing the distinctive spiral morphology.

Bacteria come in a few basic shapes, and a corkscrew-like form is described as spiral. The term for these corkscrew-shaped bacteria is spirilla. They have rigid, helical bodies and move by twisting, with classic examples in the genus Spirillum. By contrast, cocci are spherical, bacilli are rod-shaped, and protozoa are not bacteria at all (they’re a different single-celled organism). So spirilla best matches the corkscrew description, capturing the distinctive spiral morphology.