Caption:
Mitosis. Light micrograph of a whitefish cell in telophase, the last stage of mitosis (nuclear division) before cytokinesis (cell division). Mitosis is the formation of two daughter nuclei from one parent nucleus. The chromosomes have been split into their sister chromatids and moved to separate poles of the cell by microtubules (brown). Chromatids consist of deoxyribonucleic acid (DNA, black). Microtubules are protein filaments that form spindles, which attach to the chromosomes and pull the sister chromatids to opposite poles of the cell. A nuclear envelope will reform around each nucleus before the cell goes on to divide in half, with each new cell retaining a copy of the parent cell's genetic information.