1. Cell Division: Mitosis & Cytokinesis
Define mitosis and cytokinesis
Describe the cell cycle and the changes that take place during interphase
Discuss the events and significance of mitosis

2. Chromosomes Chromosomes: “colored body”
seen only when the cell divides
contain genetic info in the form of DNA
are coiled chromatin
Composition of Chromatin
Make up chromosomes
Composed of DNA and protein called histones (helps to condense the DNA)
DNA in a chromosome is 10,000x longer than the chromosome itself
Must condense in order to separate correctly during mitosis

3. Chromosome Structure Can only see chromosomes during division
Each chromosome replicates and is paired as sister chromatids joined at a centromere
Human cell has 46 chromosomes (2n)
“n” number = 23 = “haploid”
2n = 46 = “diploid”
4n = 92 (during interphase)
Body cells (aka somatic cells) = 2n = 46
Sex cells (aka eggs & sperm) = n = 23

4. The Cell Cycle ______________
Growth, prepares for division, divides (anywhere from 6 hours to 100 days)
3 Parts:
______________
______________ (PMAT) - few minutes to several days

5. Interphase – 3 stages
More than _____% of the life of a cell is spent in this phase
G1: cell growth, development, and __________ production (longest)
S: “Synthesis”, ___ replication
G2: __________ replicated (shortest)
Note: DNA exists as _________ (no chromosomes yet)

6. Mitosis - Prophase
__________ phase of mitosis (50-60 % of total time required for mitosis)
Nuclear __________ starts to disintegrate
Chromosomes condense (become visible) – seen as 2 identical __________ lying side by side held together by __________
__________ move to opposite poles
Spindle __________ grow from centrioles, attach at centromeres

7. Mitosis – Metaphase (hint “m”=middle)
Chromosomes attach to the _____________
Chromosomes line up in the middle (aka equator)
Spindle fibers run from __________ to __________ of the chromosomes

8. Mitosis - Anaphase (hint “a” = away)
__________ split
Spindles retract and pull sister __________ apart
Chromosomes move to __________ poles (toward centrioles)

9. Mitosis - Telophase Chromosomes cluster at __________
Chromosomes uncoil back into __________
Nuclear envelope reforms around each new _____
Mitosis is done
Cell __________ begins to pinch in the middle

10. Cytokinesis
Cell membrane moves __________ and pinches in the middle forming two __________ cells
In plant cells – a cell __________ (eventually becomes the cell wall) and cell membrane appear separating the 2 new cells
There are now 2 identical cells – same DNA, etc.