What are the functions of microtubules in an eukaryotic cell?
See below about the functions of microtubules
Microtubules are part of the cell skeleton and they are located in the cytoplasm. As on the picture below, they are built mostly of tubulin
Their function is to transfer substances in the cell, to perform cellular and intracellular motion (control of cellular structure motion, cell shaping and cell polarity) and microtubules participate in the division of eukaryotic cells, especially in mitosis. In mitosis they separate chromatides.
Around the spindle apparatus, during mitosis, there are three types of microtubules: kinetochore microtubules, astral rays/ fibres and polar microtubules.
More about spindle fibres:
What is the difference between astral ray and spindle fibre?