Cell Cycle Notes
This description applies to a typical eukaryotic cell.
Represents a breakthrough that allows the large genome eukaryotes to replicate.
We divide the cell cycle into five main parts:
- G1 phase
- S phase
- G2 phase
In fact this is a continuum!
- Growth phase.
- Approx. 40% of cell cycle.
- Many organisms spend most of life here.
S (synthesis) phase
- The genome is replicated.
- Approx. 45% of cell cycle.
- Preparation for mitosis.
- Organelles replicate, chromosomes condense, microtubules organized.
- Approx. 10% of cell cycle.
- Microtubules assemble, arrange chromosomes then pull them apart.
- Approx. 5% of cell cycle.
- Cell actually divides into two.
- Takes approx. 1 minute.
- Marked by the appearance of the cleavage furrow in animal cells.
- In plant cells the cell plate appears.