Cell Division (IMAGE) University of Oregon Caption A photomicrograph made using fluorescent light microscopy shows a one-cell stage Caenorhabditis elegans (roundworm) embryo undergoing cell division. Microtubules (green) are rigid protein polymers that organize, capture and move chromosomes (blue) made up of DNA. Chromosomes are in two groups, which are being pulled by microtubules towards opposite poles of the bipolar spindle. The microfilament cytoskeleton (red) is at the cell cortex just underneath the cell membrane. These longer, more flexible protein polymers must be organized into a "cleavage furrow" that pulls a circumferential ring of the cell surface into the center of the cell, ultimately dividing the single parent cell into two daughter cells at the end of cell division -- each with one complete set of chromosomes and genes. The organization and constriction of the cleavage furrow happens slightly later. Credit Courtesy of Bruce Bowerman Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.