Mitosis
description
Transcript of Mitosis
![Page 1: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/1.jpg)
Mitosis
“The Life and Times of the Cell”
![Page 2: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/2.jpg)
Objectives
List factors that influence when cells divideUnderstand & describe the ‘Cell Cycle’Study the events of cell division (Mitosis)Compare Mitosis in plant & animal cells
Cell Division Animation
![Page 3: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/3.jpg)
Reading Assignment
Read Section 10-1, p.241-243 titled Cell Growth.From the diagram indicating the Ratio of Surface area to Volume onp.243, sketch in your notes the smallest cell and the related statistics for Surface Area, Volume, and Surface Area to Volume Ratio and then sketch the largest cell with it’s related statistics.Answer the 4 questions in 10-1 Section Assessment on p.243.
![Page 4: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/4.jpg)
Cell Cycle – 4 PhasesGap 1 (G1)– Typical cell growth &
metabolism.S Phase (S)– DNA Replication
Gap 2 (G2)– Centrioles Replicate– Protein synthesis
M Phase (M)– Mitosis phase / cell division
occurs
![Page 5: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/5.jpg)
Cell Cycle
The G1, S and G2 stages of the Cell Cycle happen during INTERPHASE.The M phase consists of: Prophase;
Metaphase; Anaphase;
Telophase; Cytokinesis
![Page 6: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/6.jpg)
S Phase - DNA ReplicationAn enzyme called Helicase causes the hydrogen bonds that hold DNA together to break or ‘unzip’
Then DNA Polymerase allows free floating nucleotides to attach to the single strand of DNADNA is Replicated
![Page 7: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/7.jpg)
Draw DNA Replication
Draw a DNA triplet with the base sequence ATG on the left side. Make the 5’ the top left.
![Page 8: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/8.jpg)
DNA Replication
Separate the original DNA strands.With different colors, show the attachment of free-floating nucleotides.
![Page 9: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/9.jpg)
DNA Replication
Where do the free-floating nucleotides come from?Foods we eat!How do the 2 strands compare?They are exactly the same!What happens if there is a mistake made during replication?A mutation occurs!
![Page 10: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/10.jpg)
Replication
DNA Replication..Who wants to try?
Replication Song
![Page 11: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/11.jpg)
M Phase – Mitosis (4/5 Phases)
1. Interphase– G1, S, & G2 phases
2. Prophase– Early & Late
3. Metaphase4. Anaphase5. Telophase– Early & Late
Cytokenesis
![Page 12: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/12.jpg)
Interphase
![Page 13: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/13.jpg)
Early ProphaseReplicated centrioles split and start moving to opposite sides of the cell forming ASTERS.Nuclear envelop disappearsReplicated chromatin shortens, thickens and forms CHROMATID PAIRS
![Page 14: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/14.jpg)
Remember this Diagram?
![Page 15: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/15.jpg)
Early Prophase
![Page 16: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/16.jpg)
Late Prophase
Centrioles have reached opposite poles of the cell
SPINDLE forms
Chromatid Pairs float throughout the cytoplasm.
![Page 17: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/17.jpg)
Late Prophase
![Page 18: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/18.jpg)
MetaphaseShortest stage of Mitosis
Chromatid pairs align at the equator of the spindle
![Page 19: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/19.jpg)
Metaphase
![Page 20: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/20.jpg)
Anaphase
Chromatid pairs split
Spindle fibers contract and the single CHROMOSOMES are pulled to opposite poles
![Page 21: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/21.jpg)
Anaphase
![Page 22: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/22.jpg)
Early TelophaseOften described as the opposite of prophase
Nuclear envelop reappears
The chromosomes unravel to become chromatin
Cleavage furrow begins to form
![Page 23: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/23.jpg)
Late Telophase
Cleavage furrow completes it’s indentation.“Mother” cell splits into 2 identical “Daughter” cells in a process called CYTOKINESIS
![Page 24: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/24.jpg)
Early/Late Telophase
![Page 25: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/25.jpg)
Summary of MitosisProphase:
Replicated chromatin condense into chromatid pairCentrioles move to opposite polesNuclear envelope disappearsSpindle fibers start to form
MetaphaseChromatid pairs line up at the equator
AnaphaseChromatid pairs splitChromosomes are pulled to opposite poles by the spindle fibers
TelophaseChromosomes de-condense into chromatinNuclear envelope reappearsCytoplasm is divided into 2 cells Cytokinesis
![Page 26: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/26.jpg)
Mitosis
I don't watch television when I can talk about Cell Division!
![Page 27: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/27.jpg)
One more Phase – GAP 0 (G0)Some cells do not replicate their centrioles during Prophase.
They lose their ability to divide
They enter the Gap 0 stage
Neurons of the Spinal cord / Brain cells
![Page 28: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/28.jpg)
Mitosis in Plant vs. Animal CellsThe Rivalry Continues
Plants have no centrioles but still form spindle fibersPlant cells divide from the inside outCell Plate“Messy Metaphase”
![Page 29: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/29.jpg)
Plant Cell Mitosis
![Page 30: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/30.jpg)
Importance of Mitosis
Method of reproduction for all single celled organisms
Allows us to regenerate cells (tissue) repair cuts, bone breaks, etc
Growth – one cell to trillions
![Page 31: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/31.jpg)
How Long does the Cell Cycle Last?
Pick up a textbook and turn to page 249.
Read the section titled “Life Spans of Cells” and answer the 4 questions that follow.
![Page 32: Mitosis](https://reader035.fdocuments.in/reader035/viewer/2022070422/568163c7550346895dd4fb2a/html5/thumbnails/32.jpg)
Regulating the Cell Cycle
Turn in your textbook to page 250. Read pages 250 to 252.Answer the 5 questions that follow.
Terms: Contact Inhibition; Cyclins; Internal regulators; External regulators; Cancer;