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.
expedience (countable and uncountable, plural expediences) ( 1 uncountable) The quality of being fit or suitable to effect some desired end or the purpose intended; propriety or advisability under the particular circumstances of a case. Sharp To determine concerning the expedience of action. 2  Speed, haste or urgency.