Metaphase(redirected from Metaphasic)
Also found in: Dictionary, Thesaurus, Medical.
Related to Metaphasic: metaphase plate
one of the stages of mitotic cellular division.
Two periods of metaphase are distinguished. The first is metakinesis, during which the chromosomes concentrate in the equatorial region of the spindle and form what is called the equatorial plate. There are a number of hypotheses regarding the mechanism of metakinesis; the trajectories of the chromosomes have been described, and maps have been drawn of the paths of the centromeres and arms of the chromosomes.
The second period of metaphase is metaphase proper, during which links are established between the chromosomal threads of the spindle and the centromeres, the chromosomes separating into chromatids. Metaphase lasts from 0.3 to 175 min in different cells. In meiosis the analogous stage of the first division is called metaphase I.