This educational CD-ROM represents an entirely new approach to understanding chromosome behaviour in mitosis and meiosis and their relationship to genetics, sex, life cycles and development. There are four programme sections: Information, Mitoses, Meiosis, and Test. Each can be entered at three levels of understanding (introductory - advanced - expert), with easy movement between levels. The highly intuitive user interface is built around large numbers of innovative 3D images obtained from state-of-the-art confocal microscopy. Added to these images are annotations, animations, live mitosis, schemes and text presentations. Information on the materials and techniques used and a comprehensive illustrated glossary of terms are included. Interactive questions support testing understanding of key issues. This unique CD-ROM provides essential resource material for schools, universities, research laboratories and individuals. This CD-ROM is a "must" for everyone interested in cell biology and chromosomes.