Question

The motile bacteria are able to move by

• A. fimbriae
• B. flagella
• C. cilia
• D. pili.

Answer 1

The Correct Option is B

To understand how motile bacteria move, we first need to know about the structures involved in bacterial locomotion:

• Fimbriae: These are hair-like structures on the surface of some bacteria. They are primarily used for attachment to surfaces and not for movement.
• Flagella: These are long, whip-like structures that extend from the cell body. Bacteria move by rotating their flagella like a propeller, which propels them through liquid environments.
• Cilia: These are short, hair-like structures that are found on the surface of some eukaryotic cells. They beat in coordinated waves to move the cell or move fluid over the cell surface. Bacteria, being prokaryotes, do not have cilia.
• Pili: These are similar to fimbriae but are usually involved in the transfer of genetic material between bacterial cells and are not used for movement.

Given these explanations, the correct answer to the question is flagella. Bacteria that are capable of movement, or motility, primarily do so by using flagella. The flagella rotate either clockwise or counterclockwise to propel the bacteria through a liquid medium.