Question

1. Which of the following is true in regard to bacterial motility?

A. A bacterial run is the counter clockwise motion of the cilia

B. Bacteria increase the length of their tumbles to move towards a chemokine

C. E. coli have peritrichous flagella that splay out when moving in a clockwise motion called a tumble

D. Bacterial flagella have the same basal body and hook region structure as eukaryotic flagella

The subject is medical microbiology

Answer 1

The correct option is C. i.e. E. coli have peritrichous flagella that splay out when moving in a clockwise motion called a tumble.

• Most bacteria show chemotaxis. Chemotaxis is phenomenon in which bacteria and various other single cell or multicellular organism show movement in response to chemicals present in environment.
• Their are two types of chemicals chemorepellents and chemoattractants.
• E.coli have several flagella (4-12) per cell which can move in clockwise and counterclockwise direction.
• E.coli tumbles in place buy breaking the flagella bundle apart so that each flagellum points towards different direction. this motion occurs in clockwise direction.
• In counter-clockwise, all the flagella comes together as a bundle and bacteria moves or swim in straight line.