English: This figure shows two models regarding assembly and organization of the mitotic spindle. On the left is the conventional search-and-capture model in which microtubules emanating from microtubule organizing complexes undergo repeated growth and catastrophe until they bind and are stabilized by kinetochores. Biorientation promotes alignment of chromosomes at the cell equator. On the right is another model that describes the ability of microtubules to self-organize into a spindle-like structure due to their dynamics and the space constraints of the the cell.