Answer:
Pilus
Explanation: Bacteria are prokaryote with single cell and are microscopic in nature.
Pilus at protein structure located in bacterial chromosome they are attach to it surface and aids adhesion to cell surfaces,structures and host cells. Pilus contains adhesin which is located along the pilus its aid the attachment of pilus to cells
There are three basis steps in bacterial attachment; Adsorption,Adhesion and adherance