How do bacilli and spirilla move?

How do bacilli and spirilla move?

• A. Flagella
• B. Cilia
• C. Pili
• D. Slender hair-like extensions for locomotion

Answer: (A)

Bacteria move with flagella. Flagella are long, whip-like appendages that rotate to propel the cell through liquid, giving bacilli and spirilla the ability to swim toward favorable conditions or away from harm. Cilia are not found in bacteria; they’re on some eukaryotic cells and beat in coordinated waves. Pili are primarily for attachment or genetic exchange, not for locomotion. The description “slender hair-like extensions for locomotion” hints at the same idea, but the precise term used is flagella, which is why it’s the best answer.

Bacteria move with flagella. Flagella are long, whip-like appendages that rotate to propel the cell through liquid, giving bacilli and spirilla the ability to swim toward favorable conditions or away from harm. Cilia are not found in bacteria; they’re on some eukaryotic cells and beat in coordinated waves. Pili are primarily for attachment or genetic exchange, not for locomotion. The description “slender hair-like extensions for locomotion” hints at the same idea, but the precise term used is flagella, which is why it’s the best answer.