Hello Aspirant,

I hope you are doing well.

The Monera is divided into three subkingdoms: cyanobacteria, archaea, and eubacteria (also known as true bacteria). Bacteria, especially pathogenic bacteria, have filamentous appendages that help them  attach to  host cells. This thread-like structure is made up of pilin proteins. This appendage is known as cilia. Fimbria is shorter than pili. Pili is also made up of piling protein. Pili helps bacteria to transfer genetic material during conjugation. Rhizoid is a rootlike structure present in liverwort, mosses, and fungi to provide attachment to the substance. Mesosomes help to increase the area of bacterial cells. It is a folded cavity or pouch in the cell membrane. Algae have a rootlike structure for attachment with moist stones, soils, and wood. This rootlike structure in algae is holdfast.

I hope this helps.

Good Luck.