The structures that help some bacteria to attach to rocks and/or host tissues are:
Fimbriae
Mesosomes
Holdfast
Rhizoids
Correct answer: Fimbriae
Solution
Fimbriae are short, numerous surface appendages that help bacteria adhere to rocks, tissues, and other surfaces. They are especially important in colonization and infection, unlike mesosomes, holdfasts, or rhizoids.