1. Cell Division

2. BIG PICTURE: Cell Division of Human Cells 46
GOAL: To make cells w/ SAME amount of DNA
1. Interphase
Cell copies DNA 92
2. Mitosis
Divides DNA Equally 46
3. Cytokinesis
Cytoplasm divides/Cell splits 46
BIG PICTURE:
Cell Division of Human Cells

3. Why do cells divide? To create new life:
zygote divides to become ball of cells

4. Why do cells divide? To replace old cells:
Rarely divides
To replace old cells:
Different cells divided at different rates
How fast do
Cells divide?
Divides once/day
Never divides
Rarely divides
Divides once/year

5. Why do cells divide? To help an organism grow:
adding cells makes organism bigger

6. Why do cells divide? To heal from injury:
new cells fill in to help repair

7. Learning Terms Thin/Stringy DNA seen in interphase Tightly coiled DNA
Seen in mitosis
Exact copies
centromere
Chromatin
Chromosome
Duplicated
Chromosome

8. Interphase THINK! – What 2 things happen during interphase? Cell grows
Cell copies (doubles) its DNA

9. Mitosis (4 Phases) The cell divides the DNA molecules equally
THINK! – A mosquito normally has 6 DNA molecules. How many molecules will each cell have after mitosis?
THINK! – Humans normally have 46 DNA molecules. How many molecules will each cell have after mitosis? 6 46

10. Phase 1: Prophase (P= Prepare)
Chromatin coils into chromosomes
Nucleus disappears
Spindle fibers appear

11. Phase 2: Metaphase (M= Middle)
Spindle fibers move the duplicated chromosomes into the middle of the cell

12. Phase 3: Anaphase (A=Apart)
Duplicated chromosomes split at the centromere
Spindle fibers pull chromosomes to opposite sides of the cell

13. Phase 4: Telophase (T= Tear/Two Nuclei)
Chromosomes uncoil into chromatin
Nucleus reappears
Spindle fibers disappear

14. Cytokinesis THINK! – What happens?
Cytoplasm and organelles divided (cell splits)

15. Cytokinesis: Animal vs. Plant
Animal Cells
Cell membrane pinches inward
Plant Cells
Hard Cell plate forms in center

16. Visualizing Mitosis! ACTIVITY Mitosis Hybrid Medical Animation
INTERACTIVE ACTIVITY TO TRY WITH THE CLASS!
Mitosis Hybrid Medical Animation
Mitosis with Music
Brain-Pop Clip (Mitosis)
Streaming Animations
Glencoe Mitosis Animation
United Streaming (Mitosis_ 1:18)
Real-Time Animations
Animal Cell Mitosis (Just click on “LIVE ANIMAL MITOSIS”)
Plant Cell Mitosis (Just click on “PLANT CELL MITOSIS”)
Helpful Websites
Cells Alive -
Biology Corner