1. The Cell Cycle and Mitosis
Cell Division in Prokaryotes
Prokaryotes hav one circular chromosome
Binary Fission- the division of a prokaryotic cell into two offspring cells
DNA is copied, forming two identical chromosomes
Cell grows until it reaches approximately twice the cell’s original size

2. Cell division in Eukaryotes
Cell Cycle –repeating set of events in life of cell
Interphase- time between cell divisions
G1 phase- cells grow to mature size
S phase- cell’s DNA is copied (synthesized)
G2 phase- Time during which cell prepare fro cell division
Cell Division:
Mitosis- the nucleus of cell divides
Cytokinesis- division of cell’s cytoplasm

3. Cell division in Eukaryotes https://wps. prenhall

4. Stages of Mitosis Prophase DNA condenses into chromosomes
Centrosomes move to opposite poles
Mitotic spindle starts to form

5. Metaphase Anaphase Chromosomes move to center of dividing cell
Chromatids of each chromosome separate and move toward opposite poles

6. Telophase Spindle fibers disassemble
Chromosomes return to a less tightly coiled chromatin state
Nuclear envelope forms around each set of chromosomes
Nucleolus forms in each of the newly forming cells

7. Cytokinesis- division of cytoplasm
In Animal Cells
Cytokinesis begins with a pinching inward of the cell; cleavage furrow
Cleavage furrow pinches the one cell into two cells
In Plant Cells
Vesicles from Golgi apparatus join together at midline of dividing cell to form Cell Plate

8. Control of Cell Division
Control occurs at 3 main checkpoints
Cell growth (G1) checkpoint- if cell is healthy and has grown to suitable size during G1 phase, proteins initiate DNA synthesis (S phase)
DNA synthesis (G2) checkpoint- DNA repair enzymes check the results of DNA replication. IF ok, then cell proceeds with mitosis
Mitosis checkpoint- if cell passes this checkpoint, proteins signal the cell to exit mitosis.
Cancer, the uncontrolled growth of cells is caused by mutations in the checkpoint proteins