These micrographs of a living Haemanthus (lily) cell were taken at the times indicated using differential-interference-contrast microscopy. The cell has unusually large chromosomes that are easy to see. At the light microscope level shown here, the major events of cell division have been known for more than 100 years. (A) Prophase: the chromosomes have condensed and are clearly visible in the cell nucleus. (B) and (C) Prometaphase:the nuclear envelope has broken down and the chromosomes are interacting with microtubules that emanate from the two spindle poles. Plants do not have centrioles, but their spindle poles contain proteins related to those found in the centrosomal matrix of animal cells. Note that only 2 minutes have elapsed between the stages shown in (B) and (C). (D) Metaphase: the chromosomes have lined up at the metaphase plate with their kinetochores located halfway between the two spindle poles. (E) Anaphase: the chromosomes have separated into their two sister chromatids, which are moving to opposite poles. (F) Telophase: the chromosomes are decondensing to form the two nuclei that are seen later [marked N in (G)]. (G) and (H) Cytokinesis: two successive stages in the formation of the cell plate(a new cell wall) are shown; the cell plate appears as a line whose direction of outgrowth is indicated by arrows in (H). (Courtesy of Andrew Bajer.)