S-Phase

We refer to the synthesis phase as the S phase. In this phase, DNA, the building block of chromosomes, is produced in the cell nucleus = replication. The normal chromosome number is specific for each species and is 46 in humans. Cancer cells often have additional chromosomes. The aim of this phase is to duplicate the genetic material. Cells in the S phase are particularly sensitive to external influences, e.g. cytostatic drugs. The S-phase lasts 5-10 hours for most cells.