what’s the point??? asexual reproduction…. three reasons why cells reproduce by asexual...
TRANSCRIPT
What’s the point???What’s the point???
Asexual Reproduction…Asexual Reproduction…
Three reasons why cells reproduce by asexual reproduction: 1. Growth 2. Repair 3. ReplacementCell that reproduce by asexual reproduction reproduce constantly. Skin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun.
Two Basic Types of Cells – Quick ReviewTwo Basic Types of Cells – Quick Review
Prokaryote
Eukaryote
Asexual Reproduction in Asexual Reproduction in Prokaryotes = Binary FissionProkaryotes = Binary Fission
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Asexual ReproductionEukaryotes = Mitosis
Adapted, In part, from Mrs. Camp
7th Grade Life Science
Cell Life Cycle - Overviewhttp://www.cellsalive.com/mitosis.htm
• Interphase
• Prophase (mitosis)
• Metaphase (m)
• Anaphase (m)
• Telophase (m) & Cytokinesis
http://www.biology.arizona.edu/Cell_bio/tutorials/cell_cycle/mitosis_movie.html
Interphase occurs before mitosis begins
• Chromosomes are copied (# doubles)• Chromosomes appear as threadlike coils
(chromatin) at the start, but each chromosome and its copy(sister chromosome) change to sister chromatids at end of this phase
CELL MEMBRANENucleus
Cytoplasm
InterphaseInterphase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Prophase 1st step in Mitosis
• Mitosis begins (cell begins to divide)• Centrioles (or poles) appear, divide and begin to move to opposite end of the cell. • Spindle fibers form between the poles.• Chromosomes(Chromatin)begin to coil around a spindle shaped protein and become ChromatidsNuclear membrane begins to break apart
CentriolesSister chromatids
Spindle fibers
Chromatids - ProfilesChromatids - Profiles
ProphaseProphase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Spindle fibers
Centrioles
Metaphase 2nd step in Mitosis
• Chromatids (or pairs of chromosomes) attach to the spindle fibers.
Centrioles
Spindle fibers
MetaphaseMetaphase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Anaphase 3rd step in Mitosis
• Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell.
Centrioles
Spindle fibers
AnaphaseAnaphase
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Telophase 4th step in Mitosis
• Two new nuclei form. • Chromosomes appear as chromatin (threads
rather than rods).• Mitosis ends.
NucleiNuclei
Chromatin
TelophaseTelophase
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 Mitosis -- Review
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
Plant Mitosis -- ReviewInterphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
How much time is in each phase?How much time is in each phase?
The Most Time is in the INTERPHASE The Most Time is in the INTERPHASE – (G1, S & G2)– (G1, S & G2)
Time to Play (or Make a Play)Time to Play (or Make a Play)
ROLESChromosomes (4)
(later Chromatids – must have belts)
Centrioles (2)Nuclear Membrane
(6)Cell Membrane (16)Golgi Body (2)Mitochondria (2)
Action PartReplicate and divide
Pull apart the sister chromatids
Dissolve and reappear
Divide along equator of cell
Move into your new homes
Cell CycleCell Cycle
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The Cell CycleThe Cell Cycle
25
- Cell Division
25
Mitosis AnimationMitosis Animation
http://www.cellsalive.com/mitosis.htm
http://www.biology.arizona.edu/Cell_bio/tutorials/cell_cycle/mitosis_movie.html
Song Challenge…Song Challenge…
SONG TIME: http://www.teachertube.com/viewVideo.php?video_id=81750
What differs between plant cell What differs between plant cell and animal cell mitosis?and animal cell mitosis?
How are mitosis and binary fission How are mitosis and binary fission different?different?
Meiosis KM 30
Asexual Reproduction – So Cool!Asexual Reproduction – So Cool!Common Types:1. Splitting2. Budding3. Parthenogenesis4. Fragmentation◦Almost all single-celled
organisms reproduce asexually.
◦Some multicellular organisms can reproduce asexually too, produce clones (offspring genetically identical to parent).
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ReferencesReferences
3. GIF of binary fission is from: http://www.slic2.wsu.edu:82/hurlbert/micro101/pages/Chap2.html#two_bact_groups
2. http://library.thinkquest.org/12413/karyotes.html
1.http://74.125.113.132/search?q=cache:PKemMRTlT_kJ:sciencespot.net/Media/mitosisPPT.ppt+mitosis+powerpoint&cd=1&hl=en&ct=clnk&gl=us&client=firefox-a
4.http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookmito.html