Mitotic Spindle Apparatus (IMAGE) University of Basel Caption Mitotic spindle apparatus preparing for chromosome segregation: an unaligned chromosome activates the checkpoint (green) and thereby prevents premature segregation. Credit © University of Basel, Biozentrum Usage Restrictions Give adequate attribution to the original author. 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.