The correct sequence of events is a robust characteristic
of the chromosome cycle. If an early event is blocked, then
usually none of the following events takes place, suggesting
that cell cycle events form a dependent sequence.
For example, if DNA replication is blocked by a drug or a
conditional mutation, then later events – mitosis and
cytokinesis – are not initiated. If mitosis is blocked, then
cell division and the subsequent S phase will not take place.
If cell growth is blocked by nutrient deprivation or
antigrowth signals, the cell cycle will arrest in G1 or G2
(depending on cell type).