1. Eukaryotic Cell Division
Occurs by Mitosis
Q: What type of cell does mitosis occur in?
A: Somatic cells or body cells (2n)

2. The Cell Cycle
Cell cycle = period from the beginning of one cell division to the beginning of the next.
Why is cell division important?

3. The Cell Cycle
Three important functions of cell division for organisms:
Growth – grow from single cell to multi-cellular organism
Maintenance – replacement of worn out cells (e.g. Blood cells)
Repair – cell division regenerates damaged tissues

4. Cells divide for an organism to survive
Result of cell division
= two new cells (daughter cells) that are identical to the original cell (parent cell)
Why are the daughter cells identical?
They contain an exact copy of the parent cell’s hereditary material
DNA (deoxyribonucleic acid)
DNA store the instructions that determine the details of the organism’s life (characteristics, functions, life span)

5. Cells divide for an organism to survive
DNA – is store in the nucleus of eukaryotic cells
- it forms thread-like coils called chromatin, which we usually can’t see
- when a cell divides, the chromatin condenses and forms chromosomes, which we can see
Guess how much DNA fits into the nucleus? 2m

6. Why is cell Replication in Eukaryotes more complicated?
complicated because:
DNA is divide among several linear chromosomes
DNA is contained within a nucleus
cell has several membrane bound organelles
Source:

7. Three Stages of the Cell Cycle
Stage 1 – Interphase
Growth and preparation of cell for division
DNA replication occurs in this stage
Consists of G1, S, G2 phases
Stage 2 – Mitosis
Division of the nucleus
Consists of 4 phases
Stage 3 – Cytokinesis
Division of the cytoplasm and organelles
Growth Stage
Division Stage

8. The Eukaryotic Cell Cycle

11. *Separation of centrosomes

12. Spindle fibres from opposite poles attach to the centromere of each chromosome

13. * Spindle fibres shorten

15. Cleavage furrow
Division of cytoplasm (cell pinches in two)
creates a cleavage furrow

16. Chromosome Structure