The structures that help some bacteria to attach to rocks and/or host tissues are :
Fimbriae
Mesosomes
Holdfast
Rhizoids
The features that assist some bacteria to cling to rocks and /or host tissues are fimbriae. Fimbriae are long filament polymeric structural proteins found on the surface of bacterial cells. They make it feasible for the bacteria to bind to certain receptor structures and colonize particular surfaces.