Transcript MITOSIS - PBworks

I. MITOSIS
A. Cell Division:
1. Needed for normal growth, repair, &
development
2. Occurs in somatic cells (body cells)
3. Daughter cells have an exact copy of
DNA of parent cell
4. Two daughter cells
B. Why Do Cells Divide?
1. Volume Limit:
a) food intake
b) waste removal
2. Volume to Surface Area Ratio
II. Cell Cycle
A. Interphase
1. Not part of Mitosis
2. 90 % time here
3. Carries out metabolic processes:
a. Making new molecules &
organelles
b. Normal growth/development
c. Cell prepare for division
4. DNA replication
5. Chromosomes are not
distinguishable (chromatin)
6. Prepares for cell division
7. Cell Cycle:
1. G1 phase (normal growth)
2. S phase (synthesis
3. G2: prepares to divide
4. Mitosis/Cytokineses
Mitosis Begins
Cell Cycle Continues
B. Prophase
1. First stage of mitosis
2. Chromosomes appear
(shorten & thicken =
sister chromatids)
3. Centrioles, spindle fibers
appear
4. Nuclear membrane
dissolves
C. Metaphase
1. Chromosomes line
up at the equator
D. Anaphase
1. Chromosomes
separate and
migrate to the
opposite ends of the
cell
E. Telophase
1. Reorganization
a)
spindle fibers disappear
b) nuclear membrane forms
2. Chromosomes lengthen &
disappear
3. Cytoplasm splits (cytokinesis)
into two daughter cells
 Cell Plate forms for plant cells
Mitosis in Animal Cells
Mitosis in Whitefish Blastula
Cytokinesis in Plant Cells
Mitosis in Plant Cells
Mitosis in Onion Root Tip
F. Significance
1. TWO Daughter cells
2. Identical DNA to parent cell
3. Healing
4.
Growth
5.
http://hybridmedicalanimation.com/anim_mitosis.html
6.
http://images.google.com/imgres?imgurl=http://iknow.net/images/scr
een_sisterchroms_512.jpg&imgrefurl=http://iknow.net/CDROMs/cell_
cdrom/cell_dvd.html&h=384&w=512&sz=33&hl=en&start=5&tbnid=J
WsP3BF4AY07QM:&tbnh=98&tbnw=131&prev=/images%3Fq%3Dm
itosis%2Bvideo%26gbv%3D2%26hl%3Den%26sa%3DG
G. Cell Cycle
1.
2.
From Individual Daughter cell  complete
cell division
Two Parts:
a. Interphase: G1, S, G2
b. Mitosis/Cytokinesis
H. Role of the Cell Cycle
A. Nearing the end of G1, two options:
1. Continue cell cycle; committed to
initiating DNA OR
2. GO (resting phase): cell remains
viable and metabolically active
but are nonproliferative (don’t reproduce)
3. Cancer cells avoid entering GO or
go through very quickly
http://images.google.com/imgres?imgurl=http://iknow.net/images/
screen_sisterchroms_512.jpg&imgrefurl=http://iknow.net/CDRO
Ms/cell_cdrom/cell_dvd.html&h=384&w=512&sz=33&hl=en&st
art=5&tbnid=JWsP3BF4AY07QM:&tbnh=98&tbnw=131&prev=
/images%3Fq%3Dmitosis%2Bvideo%26gbv%3D2%26hl%3Den
%26sa%3DG
Cell cycle
B. Tumors and Cancer
1. Tumor: mass of cells formed from out of control cell
reproduction
2. Benign tumors: abnormal mass of normal cells
-remain at original site
3. Malignant tumor: abnormal rapidly dividing cells
4. Metastasis: spread of cancer cells
http://www.youtube.com/watch?v=bDjDw18HJto
http://www.youtube.com/watch?v=rrMq8uA_6iA&NR=1
(metastasis)
C. Protein p53 (Tumor Suppressor Gene)
1. Protein to control cells w/damaged DNA:
a. code to stop cell cycle
b. repair DNA
c. program cell death
2. Mutation of p53 gene
a. found in many cancers
b. does not stop mitosis
http://www.learner.org/channel/courses/biology/archive/animations/hires/a_cancer3_h.html