cells are small! why do we need to make more cells?why do we need to make more cells?

CELLS ARE SMALL!

•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

MITOSIS 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

MITOSIS VideoParent

CellDaughter Cells

In what phase do the chromosomes line up in the middle of the cell?

ONION ROOT TIPONION ROOT TIP

Twilight DOES IT TOO!

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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