Asexual Reproduction
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Transcript of Asexual Reproduction
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Asexual ReproductionMitosis
DSQ: Mitosis is the process in which the nucleus divides to form two new nuclei. How does mitosis differ in plants and animals?
Mrs. Camp
7th Grade Life Science
How do little elephants grow up to be BIG elephants?
Why do animals shed their skin?
The process of asexual reproduction (cell life cycle) begins after a sperm fertilizes an
egg.
Three reasons why cells reproduce by asexual reproduction:
1. Growth 2. Repair 3. ReplacementSkin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun.
Cell that reproduce by asexual reproduction reproduce constantly.
Animated Cell Life Cyclehttp://www.cellsalive.com/mitosis.htm
Cell Life Cycle Stages
• Interphase
• M1- Prophase
• M2- Metaphase
• M3- Anaphase
• M4- Telophase
• Cytokinesis
Interphase occurs BEFORE mitosis begins
• Chromosomes and ALL organelles are copied.
• Chromosomes appear as threadlike coils (chromatin) at the start, but are almost invisible with a light microscope.
CELL MEMBRANENucleus
Cytoplasm
InterphaseWhat differences do you see?
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
M1- Prophase 1st step in Mitosis
• Mitosis begins. Chromosomes visible.• Centrioles (or poles) appear and begin to
move to opposite end of the cell. (Not in Plants)
• Spindle fibers form between the poles.Centrioles
Sister chromatids
Spindle fibers
M1- ProphaseWhat differences do you see?
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Spindle fibers
M2- Metaphase 2nd step in Mitosis
• Chromatids (or pairs of chromosomes) attach to the spindle fibers in middle of cell.
Centrioles
Spindle fibers
M2- MetaphaseWhat differences do you see?
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
M3- Anaphase 3rd step in Mitosis
• Chromatids (or pairs of chromosomes) separate and begin to move toward opposite ends of the cell.
Centrioles
Spindle fibers
AnaphaseWhat differences do you see?
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Telophase 4th step in Mitosis
• Chromosomes are at across ends of cell.• Chromosomes appear as chromatin
(threads rather than rods).• Two new nuclei form• Mitosis ends.
NucleiNuclei
Chromatin
TelophaseWhat differences do you see?
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Cytokinesisoccurs AFTER mitosis
• Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes.
Animal Cell Life Cycle - Review
Interphase
M1-Prophase
M2- Metaphase
M3- Anaphase
M4- Telophase
Cytokinesis
Plant Cell Life Cycle -- ReviewInterphase
M1- Prophase
M2- Metaphase
M3- Anaphase
M4- Telophase
Cytokinesis Cell Wall Plate Forms
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Cell Life Cycle- Animal Cell
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- Cell DivisionThe Cell Cycle
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Cell Life Cycle Animation
http://www.cellsalive.com/mitosis.htm