Cells divide on a regular basis to bring about growth and asexual reproduction. The cells divide in a sequence known as the cell cycle. There is a period of non-division known as interphase, when cells increase in size, mass and carry out normal cellular activities and replicate their DNA ready for mitosis. Followed by a period of active division- Mitosis, when an increase in number of cells occur. Finally cytokinesis when the new cells separate.
INTERPHASE
1. G1
2. S
3. G2
MITOSIS
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
5. Cytokinesis
PROPHASE
Chromosomes condense Homologous chromosomes pair w/ each other Each pair contains four sister chromatids
METAPHASE
homologous chromosomes move to center of cell
ANAPAHSE
Homologous chromosomes pulled to opposite poles
TELOPHASE
Daughter nuclei formed
These are diploid (2n)
WHAT HAPPENS
Chromosomes are already unraveled so that protein synthesis can occur. The DNA replicates itself
1. Nuclear envelope breaks down. Centriole divides and move to opposite poles. Spindle fibers form
2. Chromosomes move to the central region and spindle fibers attach to centromeres
3. Centromeres split. Sister chromatids separate and become individual chromosomes. Spindle fibers shorten, pulling chromosomes to opposite poles
4. Nuclear envelope forms. Spindle fibers break down and disappear
5. Cell splits into two, containing a full set of chromosomes