cell cycle cell cycle 3 steps interphase cell growth and development longest phase mitosis cell...
TRANSCRIPT
Cell CycleCell Cycle 3 Steps
Interphase
cell growth and development
Longest phase
Mitosis
cell reproduction creating 2 new nuclei
Cytokinesis
cell reproduction finishes
creating 2 new cells (DAUGHTER)
Importance of Cell Division
• Some cells get old and wear out
• New cells formed by the cell cycle replace old cells before they die– For example: every human is shedding old
skin cells. We loose about 40,000 cells every minute.
– Cells lining the stomach are replaced every week because your stomach is so acidic
• New cells formed by the cell cycle replace old cells before the cell dies.
Vocabulary Preview
• Cell Cycle• Interphase• Mitosis
– Prophase– Metaphase– Anaphase– Telephase
• Cytokinesis
• Homologous Chromosome
• Daughter Cell• Sister Chromatid• Centromere• Cell Plate
http://www.teachersdomain.org/asset/lsps07_int_devdance/
Length of a Cell Cycle• The length of a cell cycle is different for each type
of organism and every different type of cell (skin, heart, lung, etc…)
• When organisms are young and growing, the cell cycle repeats more quickly.– An example: A zebra fish grows from 1 cell to 256 cells in 15
minutes
Preview Cell Division
• http://iknow.net/player_window.html?url=media/cell_cycle_intro_auto.swf&width=360&height=285– Enlarge Screen for a bigger view
Phases of the Cell Cycle
RESULTS OF CELL DIVISION
•After Mitosis and Cell Division, the original cell, called the parent cell NO LONGER EXISTS•After the cell cycle (at the end of cytokinesis) 2 new identical cells (called Daughter cells) are created. They are genetically identical to the parent cell.
•Think Write Pair Share: What happened to the original parent cell?
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Interphase
• First Phase of the Cell Cycle
• Chromosomes (which is another name for the DNA) in the nucleus are like a bunch of spaghetti noodles.
• For each chromosome there is an identical chromosome. This identical pair is called homologous chromosomes.
• Humans have 23 pairs of homologous chromosomes.
Phase in Interphase• Interphase has three phases G1, S, and G2.
G1 Cells grow perform cell functions (do their job)
S Cells growperform cell functions (do their job)DNA is copied
G2 Cells growperform cell functions (do their job), all organelles are copied
Mitosis2nd part of the Cell Cycle
• Mitosis is a continuous process.
PMAT• It is made up of 4 phases
– Prophase– Metaphase– Anaphase– TelophasePREVIEW: http://highered.mcgraw-hill.com/sites/0073031216/student_view0/exercise13/mitosis_movie.html
Prophase
The first phase of mitosis is Prophase.
1) Chromosomes (DNA) twist (condense) into tight coils
2) Nucleus breaks apart
Metaphase
During Metaphase, all the chromosomes that are attached to the fibers move to the middle of the cell.
The pairs line up end to end, across the center of the cell.
“Meet in the middle”
AnaphaseDuring Anaphase, The chromosomes are pulled apart making 2 sister chromatids.
The sister chromatids are pulled to opposite sides of the cell
http://www.copernicusproject.ucr.edu/ssi/HSBiologyResources.htm
Telophase
During Telophase, a new nuclear membrane forms around the separated chromatids making 2 identical nuclei in 1 cell.
Cytokinesis
Cytokinesis
Viewing Cell DivisionCell Cycle, Animal Mitosis, & Plant Mitosis
Mitosis: http://www.iknow.net/player_window.html?url=media/prophase_video_auto.swf&width=360&height=285
Plant Cell Mitosis:
http://www.iknow.net/player_window.html?url=media/plant_mitosis_auto.swf&width=360&height=285
Microscopic:http://www.teachersdomain.org/asset/tdc02_vid_dnadivide/
Hand Drawn:http://www.layyous.com/Videoclips/mitosis.htm
Living Cell-Time lapse photography:http://www.phschool.com/science/biology_place/labbench/lab3/mitfilm.html
Writing to Learn
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