Efficiency . Smaller the cell = quicker it can work. Transport of Substances. Cellular communication. Ratio of surface area to volume. Other reasons for cellular division. Growth. Replace damaged cells. ID: 536979
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Presentations text content in Why does a cell divide?
Slide1
Why does a cell divide?
Efficiency Smaller the cell = quicker it can workTransport of SubstancesCellular communicationRatio of surface area to volume
Slide2
Other reasons for cellular division
GrowthReplace damaged cells
Slide3
The Cell Cycle
Cell reaches max size it stops growing or divides
Cells reproduce by growing and dividing =
cell cycle
3 main stages of cell cycle
Interphase – cell grows, replicates DNA
Mitosis – nucleus and nuclear material divide
Cytokinesis – cytoplasm divides
Slide4Slide5
3 Stages of Interphase
Gap 1 (G
1
)
normal functions
Synthesis (S)
Cell copies DNA
Gap 2 (G
2
)
Cell prepares for mitosis
Slide6
Mitosis
Cell’s DNA separates
Creates 2
identical
daughter cells
Same Number of Chromosomes
4 Stages – Prophase, Metaphase, Anaphase,
Telophase
Slide7
1. Prophase
Chromatin condenses into chromosomes X – shapedConsist of two chromatids – identical copies of DNAChromatids are connected at a centromere
Tumors begin with a single cell that reproduces by mitosis
Cells in tumors divide continuously
Metastasis:
Process in which
cells are invasive and move to other sites in the body
Slide17
The Cell Cycle and Cancer
Benign
= not cancerous
Do
not invade neighboring tissue or spread
Malignant
= cancerous
Readily
invade neighboring tissues
May
also detach and lodge in distant places – metastasis
Slide18Slide19
p. 181
4
Cell division
Mitosis
3
DNA repair
G2
1
Cell grows, doubles in size
G1
S
2
Chromosome duplication
G2/M checkpoint
G1/S checkpoint
Stepped Art
Checkpoints in the cell cycle regulate cell division
Slide20
How does it happen?
Oncogenes
are activated
Normal function: cell growth, gene
transcription
Tumor
suppressor
genes are inactivated
Normal function: DNA repair, cell cycle control, cell
death
Slide21
Tumor suppressors
“Guardian(s) of the genome”
Often involved in maintaining genomic integrity (DNA repair, chromosome segregation)
Mutations in
tumor
suppressor genes lead to the “
mutator
phenotype”—mutation rates increase
Often the 1
st
mutation in a developing
cancer
P53 and
Rb
Slide22
Causes of Cancer
Mutation
:
change in genetic
makeup
Any agent that causes cancer is called a
carcinogen
and is described as
carcinogenic
Infection
Viruses (EBV, hepatitis B, papilloma)
Bacteria (Helicobacter
)
Slide23
Lifestyle Risks
SmokingDiet high fat and low in fruits and vegetablesLack of exercise Unprotected exposure to the sun, (UV) raysObesityStressJobs – exposed to chemicals, etcRadiation
Slide24
Environmental Risks
Second hand smokePCB’sAir pollutionIndustrial pollutionChemical exposurestar from cigarettessome foods
Slide25
Inherited Risks
Less than 15% of cancers are inheritedSome families are more susceptible to getting certain cancersYou can’t inherit cancer its just that you maybe more susceptible to getting it
Slide26
Treatment
Chemotherapy
treatment
uses
medicine to weaken and destroy cancer cells in the
body
affects
the whole
body
Radiation therapy (also called radiotherapy)
high-energy rays are used to damage cancer cells and stop them from growing and dividing
local treatment; it affects cancer cells only in the treated
area
Slide27
Cancer Prevention
Healthy lifestyle
Exercise
and proper breathing
Balanced diet
Complete
rest and sleep
Water
Eating Fruit
Slide28
Explain what happens in each step of mitosis.
Agenda forReview mitosis (video?)Mitosis Cell Lab
Slide29
If a cell has 150 chromosomes how many daughter cells are created at the end of mitosis? How many chromosomes are in each cell?
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DownloadNote - The PPT/PDF document "Why does a cell divide?" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Presentations text content in Why does a cell divide?
Why does a cell divide?
Efficiency Smaller the cell = quicker it can workTransport of SubstancesCellular communicationRatio of surface area to volume
Slide2Other reasons for cellular division
GrowthReplace damaged cells
Slide3The Cell Cycle
Cell reaches max size it stops growing or divides
Cells reproduce by growing and dividing =
cell cycle
3 main stages of cell cycle
Interphase – cell grows, replicates DNA
Mitosis – nucleus and nuclear material divide
Cytokinesis – cytoplasm divides
Slide4Slide53 Stages of Interphase
Gap 1 (G
1
)
normal functions
Synthesis (S)
Cell copies DNA
Gap 2 (G
2
)
Cell prepares for mitosis
Slide6Mitosis
Cell’s DNA separates
Creates 2
identical
daughter cells
Same Number of Chromosomes
4 Stages – Prophase, Metaphase, Anaphase,
Telophase
Slide71. Prophase
Chromatin condenses into chromosomes X – shapedConsist of two chromatids – identical copies of DNAChromatids are connected at a centromere
Slide81. Prophase
Nuclear membrane disappears Spindle apparatus appearsSpindle fibers, centrioles, and aster fibers
Slide92. Metaphase
Chromatids Line up at center of cell
Slide103. Anaphase
Chromatids pull apart
Slide114. Telophase
Chromosomes arrive at the polesChromosomes unwindTwo nuclear membranes begin to formSpindle apparatus disappears
Slide12Cytokinesis
Divides cytoplasm
Animal Cells
Microfilaments constrict/pinch the cytoplasm
Plant Cells
Cell plate forms between two daughter nuclei
Cell walls then form on either side of cell plate
Slide13Slide14http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__mitosis_and_cytokinesis.html
http://www.sumanasinc.com/webcontent/animations/content/mitosis.html
Slide15https://
www.youtube.com/watch?v=L0k-enzoeOM
Slide16Cancer
Uncontrolled cell division
Tumors begin with a single cell that reproduces by mitosis
Cells in tumors divide continuously
Metastasis:
Process in which
cells are invasive and move to other sites in the body
Slide17The Cell Cycle and Cancer
Benign
= not cancerous
Do
not invade neighboring tissue or spread
Malignant
= cancerous
Readily
invade neighboring tissues
May
also detach and lodge in distant places – metastasis
Slide18Slide19p. 181
4
Cell division
Mitosis
3
DNA repair
G2
1
Cell grows, doubles in size
G1
S
2
Chromosome duplication
G2/M checkpoint
G1/S checkpoint
Stepped Art
Checkpoints in the cell cycle regulate cell division
Slide20How does it happen?
Oncogenes
are activated
Normal function: cell growth, gene
transcription
Tumor
suppressor
genes are inactivated
Normal function: DNA repair, cell cycle control, cell
death
Slide21Tumor suppressors
“Guardian(s) of the genome”
Often involved in maintaining genomic integrity (DNA repair, chromosome segregation)
Mutations in
tumor
suppressor genes lead to the “
mutator
phenotype”—mutation rates increase
Often the 1
st
mutation in a developing
cancer
P53 and
Rb
Slide22Causes of Cancer
Mutation
:
change in genetic
makeup
Any agent that causes cancer is called a
carcinogen
and is described as
carcinogenic
Infection
Viruses (EBV, hepatitis B, papilloma)
Bacteria (Helicobacter
)
Slide23Lifestyle Risks
SmokingDiet high fat and low in fruits and vegetablesLack of exercise Unprotected exposure to the sun, (UV) raysObesityStressJobs – exposed to chemicals, etcRadiation
Slide24Environmental Risks
Second hand smokePCB’sAir pollutionIndustrial pollutionChemical exposurestar from cigarettessome foods
Slide25Inherited Risks
Less than 15% of cancers are inheritedSome families are more susceptible to getting certain cancersYou can’t inherit cancer its just that you maybe more susceptible to getting it
Slide26Treatment
Chemotherapy
treatment
uses
medicine to weaken and destroy cancer cells in the
body
affects
the whole
body
Radiation therapy (also called radiotherapy)
high-energy rays are used to damage cancer cells and stop them from growing and dividing
local treatment; it affects cancer cells only in the treated
area
Slide27Cancer Prevention
Healthy lifestyle
Exercise
and proper breathing
Balanced diet
Complete
rest and sleep
Water
Eating Fruit
Slide28Explain what happens in each step of mitosis.
Agenda forReview mitosis (video?)Mitosis Cell Lab
Slide29If a cell has 150 chromosomes how many daughter cells are created at the end of mitosis? How many chromosomes are in each cell?
Agenda for
Finish lab
Finish worksheets
Start cancer notes
Slide30What is cancer?
Agenda for
Cancer Notes
Go over worksheets and lab
Cancer worksheet