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Mitosis
BODY Cell Division
(Chapter 3 : 3 p.86-89)
Mitosis is the process in which the
       nucleus divides to form two new nuclei.
Mitosis differs in plants and animals.
A form of asexual reproduction – one celldivides into two
How do little elephants grow up to be BIGelephants?
How does skin heal itself?
http://content.revolutionhealth.com/contentimages/images-image_popup-basal.jpg
Skin cancer - theabnormal growth ofskin cells - most oftendevelops on skinexposed to the sun.
Why do animals shed their skin?
There are 3 reasons why cells go through mitosis: 1. Growth 2. Repair 3. Replacement
Cells that reproduce by asexual reproduction reproduce constantly.
Animated Mitosis Cycle
http://www.ivy-rose.co.uk/Topics/Cell_Structures/Mitosis_cIvyRose.jpg
•Interphase
•Prophase
•Metaphase
•Anaphase
•Telophase
•& Cytokinesis
Interphase occurs before mitosis begins
•Chromosomes are copied (# doubles)
•Chromosomes appear as threadlike coils(chromatin) at the start, but each chromosomeand its copy(sister chromosome) change to sisterchromatids at end of this phase
CELLMEMBRANE
Nucleus
Cytoplasm
Interphase
Animal Cell
Plant Cell
animal_interphase
plant_interphase
Prophase 1st step in Mitosis
•Mitosis begins (cell begins to divide)
•Centrioles appear and begin to move toopposite end of the cell.
•Spindle fibers form between the centrioles.
Centrioles
Sister chromatids
Spindle fibers
Prophase
Animal Cell
Plant Cell
animal_prophase
plant_prophase
Spindle fibers
Centrioles
Metaphase 2nd step in Mitosis
•Chromatids (or pairs of chromosomes heldtogether by centromeres) meet in the middleof the cell and attach to the spindle fibers.
Centrioles
Spindle fibers
Metaphase
Animal Cell
Plant Cell
animal_metaphase
plant_metaphase
Anaphase 3rd step in Mitosis
•The centromere splits and the sister chromatids (orpairs of chromosomes) separate and begin to moveto opposite ends of the cell.
•The separated chromatids are now calledchromosomes.
Centrioles
Spindle fibers
Anaphase
Animal Cell
Plant Cell
animal_anaphase
plant_anaphase
Telophase 4th step in Mitosis
•A new nucleus forms around each identical groupsof chromosomes at opposite sides of the cell andtwo new nuclei form.
•Chromosomes appear as chromatin (threads ratherthan rods).
•The cell membrane starts to move inward near themiddle of the cell.
•Mitosis ends.
Nuclei
Nuclei
Chromatin
Telophase
Animal Cell
Plant Cell
animal_telophase
plant_telophase
Cytokinesis occurs after mitosis
•The cytoplasm is completely pinchedcreating two identical daughter cells – eachwith its own nucleus with identicalchromosomes.
Animal Mitosis -- Review
 Interphase                                                              
1. Prophase                                                              
2. Metaphase                                                              
3. Anaphase                                                              
4. Telophase                                                              
Cytokinesis                                                              
interphase-1
prophase
metaphase
anaphase
telophase-1
interphase-2
Plant Mitosis -- Review
Interphase                                                              
1. Prophase                                                              
2. Metaphase                                                              
3. Anaphase                                                              
4. Telophase                                                              
Cytokinesis                                                              
alliuminterphase1
alliumprophase
alliummetaphase
alliumanaphase
alliumtelophase
alliuminterphase2
In Plant cells (and other cells with cell walls), a cell plate forms before the cell splits into two. The cell wall replaces the cell plate.
http://wpcontent.answers.com/wikipedia/commons/thumb/5/5b/Phragmoplast.png/300px-Phragmoplast.png
http://www.sep.alquds.edu/biology/scripts/Biology_english/part_3_4_files/image010.jpg
Cell plate
REMEMBER!
IInterphase
PProphase
MMetaphase
AAnaphase
TTelophase
CCytokinesis
IPMATCIPMATC
I Pray More At The ChurchI Pray More At The Church
23
Cell Cycle
24
- Cell Division
The Cell Cycle
24