What bacteria, when viewed through a microscope, would appear to be spiraled, coiled, corkscrew-shaped bacterial cells?

What bacteria, when viewed through a microscope, would appear to be spiraled, coiled, corkscrew-shaped bacterial cells?

• A. Spirilla
• B. Flagella
• C. Saprophytes
• D. Staphylococci

Answer: (A)

Spiral-shaped bacteria seen under the microscope are called spirilla. Their defining feature is a rigid, helical form that twists like a corkscrew, giving a clear spiraled appearance. This shape distinguishes them from other bacteria that are spherical (cocci) or rod-shaped (bacilli). The term flagella refers to the movement structures, not the cell’s shape, so it wouldn’t describe a spiraled form. Saprophytes describe how an organism obtains nutrients, not its appearance, and staphylococci are spherical bacteria that form grape-like clusters. So the spiral, corkscrew-shaped appearance best matches spirilla.

Spiral-shaped bacteria seen under the microscope are called spirilla. Their defining feature is a rigid, helical form that twists like a corkscrew, giving a clear spiraled appearance. This shape distinguishes them from other bacteria that are spherical (cocci) or rod-shaped (bacilli). The term flagella refers to the movement structures, not the cell’s shape, so it wouldn’t describe a spiraled form. Saprophytes describe how an organism obtains nutrients, not its appearance, and staphylococci are spherical bacteria that form grape-like clusters. So the spiral, corkscrew-shaped appearance best matches spirilla.