The structures that help some bacteria to attach to rocks and/or host tissues are
- mesosomes
- holdfast
- rhizoids
- fimbriae.
Answer
(4) fimbriae.
Solution
As per NCERT, fimbriae are small bristle-like fibres sprouting out of the bacterial cell; in some bacteria they are known to help attach the bacteria to rocks in streams and also to the host tissues.
∵ Mesosomes are infoldings of the plasma membrane, while holdfast and rhizoids are attaching structures of algae and bryophytes, they are not the answer.
Answer: (4)