cells are small! why do we need to make more cells?why do we need to make more cells?
TRANSCRIPT
•Why do we need to Why do we need to make more cells?make more cells?
From One Cell to Many
Sea Urchin Cell Division
Why do we need to Why do we need to make more cells?make more cells?
•Why do we need to make Why do we need to make more cells?more cells?
Why are we one Why are we one hundred trillion hundred trillion SMALL cells and not SMALL cells and not one hundred LARGE one hundred LARGE cells?cells?
100,000,000,000,000 cells 100,000,000,000,000 cells because....because....
They need to be small!
Egg-periment
- The transport of “stuff” across the membrane limits cell size
Egg= Big CellCube= Small Cell Blue Dye= Nutrients
Put in dye and let the molecules diffuse for 3 hours
DRAW WHAT YOU THINK WILL HAPPEN
Result
Result
It takes much longer for molecules to get where they
need to go if a cell is too big!
ItIt’’s better to have lots s better to have lots of small cellsof small cells
instead of fewer instead of fewer large cells!large cells!
WHY DO WE NEED CELL DIVISION?
List 1 of the 2 reasons
Parent Cell
Daughter Cells
•Interphase
•Prophase•Metaphase•Anaphase•Telophase
Chromosome=Sister Chromatids
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1. What is a chromosome?2. Draw a diagram of one.
Label all parts
In what phase do the chromosomes line up in the middle of the cell?
ONION ROOT TIPONION ROOT TIP
Most Cells are in Interphase!
INTERPHASEINTERPHASE
PROPHASEPROPHASE
METAPHASEMETAPHASE
ANAPHASEANAPHASE
TELOPHASETELOPHASE
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
Mitosis Project 50 Points: 3 points for each (45pt) 5 Points: for directions and neatness
6. Cytoplasm 7. Nuclear Membrane 8. Chromatin 9. 3 Chromosomes 10. Centromere11. Nucleolus 12. Centrioles 13. Spindle Fibers 14. Sister Chromatids 15. Daughter cells
1.Interphase 2.Prophase 3.Metaphase 4.Anaphase 5.Telophase
Uncontrolled Cell Division = CANCER
Cancer Survivors
What causes cancer?
National Cancer Institute- Risk Factors
Most cancers develop because of changes (mutations) in genes (DNA) which lead to lose of cell division control
• Growing older• Tobacco• Sunlight• Ionizing radiation• Certain chemicals and other substances• Some viruses and bacteria• Family history of cancer• Alcohol• Poor diet, lack of physical activity, or being overweight
Mosquito 6
Fruit Fly 8
Cat 38
Carrot 18
Human 46
Dog 78
Pigeon 80
Goldfish 94
Moral:
Quality of the Genetic Material and NOT the
Quantity give an organism
complexity
HAPLOID = the number of HAPLOID = the number of different chromosomesdifferent chromosomes (mom or dad)(mom or dad)
*in humans it*in humans it’’s s 23 (N)
DIPLOID = the total number DIPLOID = the total number of chromosomes of chromosomes (mom and dad)(mom and dad)
* in humans it* in humans it’’s s 46 (2N)
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