How a flagellum works in the presence of an attractant?

Answer 1

In the presence of an attractant, the flagellum of a bacterium, such as E. coli, rotates counterclockwise, causing the organism to swim in a straight line toward the attractant—a behavior known as "taxis." This movement is facilitated by the coordinated action of multiple flagella, which bundle together. When the bacterium encounters a repellent or when the attractant concentration decreases, the flagellum may switch to clockwise rotation, leading to a tumbling motion that allows the bacterium to reorient and search for a more favorable environment.