It is that region which initiates the development of microtubules. This region is called the centrosome. It is the centrosome and not the centriole which is responsible for making spindles because what we call 'spindle fibres' are basically microtubules. This explains why plant cells and fungi can produce spindle fibres during mitosis.
expedient(Noun) A method or means for achieving a particular result, especially when direct or efficient; a resource. expedient(Adjective) Simple, easy, or quick; convenient. Most people, faced with a decision, will choose the most expedient option.
Captain Baker applied himself to this task, and used every expedient. This expedient, however, nearly proved fatal in its consequences. No need then of the expedient of pursuing your needleworks in her sight. This: It is useless to talk or to think unless it is also possible and expedient to act. For the expedient has to do with the future, about which we are liable to mistake.