This book summarises some of the major processes involved in the production of daughter cells as they have been reported from work mainly with synchronous cultures of microalgae since the technique was first developed. This book also highlights the key findings that have led to our present understanding of cell cycle processes in microalgae with particular reference to those that control daughter-cell production. Among the microalgal species that have been studied are those that divide by simple binary fission, like the diatoms (Bacillariophyceae), dinoflagellates (Pyrrophyta) and the euglenoids (Euglenophyta), as well as those, mainly represented by the green microalgae (Chlorophyta), that divide by various more complex processes of multiple fission.