Mitosis is the process of cell division. After the DNA has been replicated in the S phase of the cell cycle, the cell enters mitosis.
- One cell → two cells
- o → 0 → 8 → oo 😉
Chromosomes, mitotic chromosomes, and sister chromatids
These concepts are easily confused:
Interphase – S phase
- The DNA is copied (replicated).
- The centrosome is replicated.
- The chromatin starts to condense (pack).
- Mitotic chromosomes are formed.
- Nuclear membrane dissolves.
- Centrosomes start to move away from each other.
Structure of the (mitotic) chromosome
The DNA is wound two times around histones, and packed tightly into mitotic chromosomes.
Nuclear membrane completely dissolved.
Mitotic chromosomes tightly packed, in the equatorial plane = metaphase plate.
- Complete mitotic spindle formed.
Sister chromatids are pulled towards each pole.
Telophase & cytokinesis
New nuclear membrane starts to form.
Chromosomes are unpacked again, relaxed chromatin forms.
Two new cells form ⇒ cytokinesis.