Fimbriae (sometimes called "attachment pili") are fine filaments of protein, usually 2–10 nanometres in diameter and up to several micrometers in length. They are distributed over the surface of the cell, and resemble fine hairs when seen under the electron microscope. Fimbriae are believed to be involved in attachment to solid surfaces or to other cells, and are essential for the virulence of some bacterial pathogens. Pili (sing. pilus) are cellular appendages, slightly larger than fimbriae, that can transfer genetic material between bacterial cells in a process called conjugation where they are called conjugation pili or "sex pili" (see bacterial genetics, below). They can also generate movement where they are called type IV pili (see movement, below). COUNT 4
QSN1 What are fimbriae? ANS1 fine filaments of protein QSN2 What are fimbriae liable for? ANS2 involved in attachment to solid surfaces or to other cells QSN3 What is the diameter of fimbriae? ANS3 2–10 nanometres QSN4 What are pili? ANS4 cellular appendages