Question

Fimbriae in prokaryotes is used for

• A. Motility
• B. Attachment or adhesion
• C. Conjugation
• D. Motility, attachment and conjugation

Hint:

• Fimbriae Short, numerous, hair-like appendages for adhesion/attachment.
• Pili (Sex Pili/F-Pili) Longer, less numerous than fimbriae, involved in bacterial conjugation. Some types of pili (Type IV) are involved in twitching motility.
• Flagella Long, whip-like structures for motility (swimming).

Answer 1

The Correct Option is B

Fimbriae (singular: fimbria) are short, hair-like proteinaceous appendages found on the surface of many prokaryotic cells (bacteria). Their primary function is to enable the bacteria to attach or adhere to surfaces, including host tissues (in pathogenic bacteria, facilitating colonization) or other bacteria (e.g., in biofilm formation).

• (a) Motility: Motility in most bacteria is primarily achieved by flagella (singular: flagellum), which are longer, whip-like appendages. Some specialized motility like twitching motility can involve type IV pili, which are different from fimbriae.
• (c) Conjugation: Bacterial conjugation, the transfer of genetic material between bacteria, is typically mediated by specialized structures called sex pili (or F-pili), which are generally longer and fewer in number than fimbriae.
• (d) Motility, attachment and conjugation: While some pili (related structures) are involved in motility and conjugation, the primary role of fimbriae is adhesion.

Therefore, fimbriae are mainly used for attachment or adhesion. \[ \boxed{\text{Attachment or adhesion}} \]