During metaphase, the chromosomes, attached to the kinetochore microtubules, begin to align in one plane (the metaphase plate) halfway between the spindle poles. The kinetochore microtubules exert tension on the chromosomes and the entire spindle-chromosome complex is now ready for the next event. The photomicrograph above depicts onion root tip cell chromosomes in metaphase, ready for separation. The kinetochore and polar microtubules are clearly visible and radiate out the ends of the cell leaving the chromosomes in the middle of the complex.