Answer: Microtubules are found in cilia and flagella .Microtubules are the thickest type of cytoskeleton fiber .Structurally they are hollow tubes that can dissolve and reform very quickly.Functionally, they provide movement to the to the organelles and pull the chromosome to their poles at the time of cell division . In cilia and flagella the microtubules are organised in such a way that it becomes a circle of nine double microtubules on the outer side and two microtubules in the center.
Tropism can be called positive or negative. Positive tropism is movement or growth towards a stimulus, whereas negative tropism is the movement or growth away from a stimulus.
