Download Mitosis/Cell Cycle PP

How does your skin repair itself
when you get a cut?
Why do cells divide?
1.) Growing organisms need more cells
– What would happen if your cells stopped dividing?
– Skin cells…what would happen if your skin cells
stopped dividing?
2.) To replace damaged or worn out cells
– Bloody knee
– Peeling skin after a sunburn
3.) As cells grow, their volume is far too big for
their surface area, and they can’t get nutrients
in and waste out fast enough
What is the goal of cell division?
• To produce two identical cells called daughter
cells.
PARENT CELL
TWO IDENTICAL
DAUGHTER CELLS
The Cell Cycle
2 Major Phases of Cell Division
1.) Interphase
G1 Stage – primary growth phase
S Stage- synthesis; DNA replication
G2 Stage – secondary growth phase
2.) Cell division (M-Phase)
M – Mitosis
C - Cytokinesis
Interphase – G1 Stage
• 1st stage after cell division
• Cells mature by making more
cytoplasm and organelles
• Cell carries on its normal,
everyday metabolic activities
• *This is the longest stage of
the cell cycle
Interphase – S Stage
• Synthesis stage
• DNA is copied or
replicated
PARENT DNA
*Why is it important that
each new cell is IDENTICAL to
the parent cell?
- Two identical copies of DNA
- Each new cell is identical to the parent cell
Keeping Cells Identical
• The instructions for making cell parts are
encoded in the DNA, so each new cell must
get a complete set of the DNA molecules
DNA replication occurs in S
stage in the parent cell
PARENT DNA
Interphase – G2 Stage
• 2nd Growth Stage
• Occurs after DNA has been
copied
• All cell structures needed for
division are made (e.g.
centrioles)
• Both organelles & proteins are
synthesized
• Everything must be in order for
the cell to divide
• **Critical Checkpoint
Cell Division M-Phase
(Mitosis and Cytokinesis)
• Mitosis (division of the
nucleus)
– Divided into 4 stages
– 1.)Prophase
– 2.)Metaphase
– 3.)Anaphase
– 4.)Telophase
• Cytokinesis evenly divides
the cytoplasm
So how does your skin repair itself
when you get a cut?
Cellular division!
When you cut your skin, the cells at the edge of
the injury are stimulated to divide rapidly
....interphase begins!
Cells where mitosis
occurs in YOUR body
Cell Type
-Skin Cell
-Red Blood Cell
-Liver Cell
-Internal linings
(Intestines)
Lifespan
life span = 2 weeks
life span = 4 months
life span = 300-500 days
life span = 4-5 days
In your groups discuss…
1.) How do cancer cells grow?
2.) How does chemotherapy fight cancer (and
what cause negative side effects?)
http://ed.ted.com/lessons/how-do-cancer-cellsbehave-differently-from-healthy-ones-georgezaidan