1. 5.1: The Cell Cycle
Mitosis: cell division that results in duplicate copy of an original cell containing the exact amount of genetic information.
Happens in all somatic cells
A cell’s total inherited amount of DNA is called its genome.

2. The Cell Cycle Interphase  Mitosis  Cytokinesis
Interphase: the growth phase in which cells make new molecules to increase its volume and mass
Further subdivided into the G1, S, and G2 phases
G1 phase: Gap 1  Rapid growth and metabolic activity
S phase: Synthesis phase  DNA synthesis and replication
G2 phase: Gap 2  Centrioles replicate, cell prepares for cell division

3. Mitosis
Division of the cell’s nucleus where the daughter cells receive the exact number of chromosomes and genetic makeup as the parent cell
Consists of the four phases: prophase, metaphase, anaphase, telophase

4. Stages of Mitosis (Interphase) Prophase Metaphase Anaphase Telophase
These 5 stages can also be subdivided into early and late stages.
ex: Early telophase, late telophase

7. Interphase During this time, the nucleus is NOT actively dividing
The growth phase in which cells make new molecules to increase its volume and mass
Chromosomes are spread out in a delicate network called chromatin
Replication of chromosomes and centrioles

8. Prophase Centrioles move to opposite sides of the nucleus
Chromosomes start to shorten and thicken
Nuclear membrane begins to breakdown
Spindle fibres form (pathway for chromatids)

9. Metaphase Paired chromatids line up at the EQUATOR of the cell
The centromere of each chromosome attaches to its respective spindle fibre
Nuclear membrane no longer apparent

10. Early Anaphase Mid Anaphase Late Anaphase
Spindle fibres contract (shorten)
Centromere splits between chromatids
Mid Anaphase
Chromatids separate and move to opposite poles (centrioles)
Late Anaphase
Chromatids arrive at opposite sides of cell

11. Early Telophase Late Telophase
Nuclear membrane reappears
Chromosomes look less thick and appear as thin threads of chromatin again
Spindle fibres disappear
Nuclear division complete: daughter cell
Late Telophase
Cytokinesis occurs and cytoplasm divides
Cell membrane pinches the 2 cells apart at the equator

13. Cytokinesis Cell division
The separation of the cytoplasm by a new cell membrane or cell wall to form two new daughter cells
and Cytokinesis
Cdck- cell division activity

14. Mitosis Animation

15. Errors in Mitosis Mutations
Cause a permanent error, or change, in the normal DNA molecules
Can be caused by various mutagens such as toxic compounds, radiation, or viruses
Mutations are passed on during anaphase and therefore are found in a localized group of cells

16. FHIT Oncogenes Found on chromosome 3
Mutation causes the FHIT gene to undergo mitosis much more rapidly causing the formation of a tumour
Oncogenes
Genes that can be activated by a mutation
Retinoblastoma, Wilms tumour, breast cancer