Presentation on theme: "Cell Growth and Revision"— Presentation transcript:
1 Cell Growth and Revision CHAPTER 5Cell Growth and Revision
2 Why do cells reproduce? GROWTH REPAIR ________________________
3 Life Spans of Body Cells ______________________ Stomach lining cells: 2 daysLife SpansofBody Cells______________________Platelets: 10 daysSkin Cells: 20 days______________________Red Blood Cells: 120 days____________________________________________Brain cells: yearsIntestinal lining cells: 3 days______________________
4 Chromosomes DNA plus proteins is called chromatin. chromatidtelomerecentromereOne half of a duplicated chromosome is a chromatid.Sister chromatids are held together at the centromere.Telomeres protect DNA and do not include genes.Condensed, duplicated chromosomeCondensed, duplicated chromosome
5 The Cell CycleThe four stages of the cell cycle are gap 1, synthesis, gap 2, and mitosis.1) Gap 1 (G1): cell growth and normal functions2) DNA synthesis (S): copies DNA3) Gap 2 (G2): additional growth4) Mitosis (M): includes division of the cell nucleus (mitosis) and division of the cell cytoplasm (cytokinesis)Mitosis occurs only if the cell is large enough and the DNA undamaged.
6 Mitosis Interphase prepares the cell to divide. Mitosis and cytokinesis produce two genetically identical daughter cells.Parent cellcentriolesspindle fiberscentrosomenucleus withDNAInterphase prepares the cell to divide.During interphase, the DNA is duplicated.
7 Steps of Mitosis Prophase Metaphase Anaphase Telophase PMAT _______________________________________PMAT
8 PROPHASE Sister Chromatids Nuclear Membrane Centrioles Fibers Shorten and ThickenBegins to break downMove apart from one anotherForm between centrioles
9 METAPHASE Sister Chromatids Nuclear Membrane Centrioles Fibers Become attached to the fibers. Are pulled to middle of cellAre stretched between the two ends of cellRemains dissolvedMove to opposite ends of cells
10 ANAPHASE Sister Chromatids Nuclear Membrane Centrioles Fibers Pulled apart by fibers.Each chromatid is separate from its “sister”Still at cell’s poles;Pull each chromatid toward opposite ends of cellRemains dissolved
11 TELOPHASE Sister Chromatids Nuclear Membrane Cell Membrane Fibers Each end of cell has a complete set of chromosomes.Begins to pinch, forming two new cellsBegin to disappearBegins to reform
12 Mitosis Cytokinesis differs in animal and plant cells. In animal cells, the membrane pinches closed.In plant cells, a cell plate forms.
13 Result in two IDENTICAL daughter cells The Point of MitosisResult in two IDENTICAL daughter cellsEach cell will have the SAME numberof chromosomes as the original cell.Each cell will have the SAME job as the original cell.
14 Understanding Mitosis Starting with prophase, draw a cell undergoing mitosis.Your original cell has 8 chromosomes.Make sure to include the cell membrane,nuclear membrane, chromosome,centrioles, and fibers.PROPHASEANAPHASEMETAPHASETELOPHASE
15 INTERPHASE PROPHASE METAPHASE ANAPHASE TELOPHASE Cell’s Life Cycle: Mitosis:ProphaseMetaphaseAnaphaseTelophaseINTERPHASE____________________________________________________________PROPHASEMETAPHASEANAPHASETELOPHASE________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
17 Plant Cell vs. Animal Cell MITOSISPlant Cell vs. Animal CellThe process is VERY SIMILAR in each type of cell.There are only 2 differences:Plant cells do not have centriolesA cell wall is laid down at the end of the cell division.
18 Can You Put These Cells In The Correct Sequence Of Mitosis? ??So What Is This??3. Anaphase2. Metaphase_________________________________________________________??So What Is This??1. Prophase4. Telophase_________________________________________________________
19 Mitosis is only a small part of a cell's "LIFE CYCLE"_____________________________(Just like you; You will only spend a short time of your life actually reproducing!")At least...LET'S HOPE SO!INTERPHASEThe cell spends most of its life in_____________________________(The phase IN-BETWEEN mitosis)Life Cycle Animation
20 Can You Put These Cells In The Correct Sequence Of Mitosis? 3. AnaphaseInterphase2. Metaphase_________________________________________________________1. Prophase4. TelophaseInterphase_________________________________________________________
21 An organism's cells are in different parts of their life's cycle. Rates of MitosisAn organism's cells are in different parts of their life's cycle.Can you identify the phases of this plant's cells?______________________________________________________________
22 Changes in the Rate of Mitosis Changes often occur in the growth rate of cells.Faster Rate of Mitosis:CANCER_______________________Slower Rate of Mitosis:AGING_______________________
23 Cancer Cell division is uncontrolled in cancer. Cancer cells form disorganized clumps called tumors.Benign tumors remain clustered and can be removed.Malignant tumors metastasize, or break away, and can form more tumors.cancer cellbloodstreamnormal cell
24 Cancer Cancer cells do not carry out necessary functions. Cancer cells come from normal cells with damage to genes involved in cell-cycle regulation.
25 Cancer Carcinogens are substances known to promote cancer. Standard cancer treatments typically kill both cancerous and healthy cells.
26 Chemicals used on household items CANCER CAUSERSSOME VIRUSESRADIATION1._________________________2._________________________SunX-Rays____________________________CHEMICALS3._________________________Chemicals used on household itemsand/or pesticidesNuclear WastesDrugs__________________ __________________ ____________________
27 CHROMOSOMES OF ORGANISMS “GUESSTIMATE”ACTUAL CHROMOSOME #CATDOGCHIMPANZEEEARTHWORMGOLDFISHCARROTLETTUCEONIONCHICKENGUINEA PIGHUMANMOSQUITOPEAPENICILLINCORNFROG32784836941818167864466141-42026
28 Chromosome Comparisons If an organism has more chromosomes,does that mean it is smarter?NOIf an organism has more chromosomes,does that mean it is larger?NOIf an organism has more chromosomes,does that mean it is more complex or evolved?NO
29 Stem cells are unique body cells. Stem cells have the ability todivide and renew themselvesremain undifferentiated in formdevelop into a variety of specialized cell types
30 Stem Cells Stem cells are classified into three types. totipotent, or growing into any other cell typepluripotent, or growing into any cell type but a totipotent cellmultipotent, or growing into cells of a closely related cell family
31 Stem Cells Stem cells come from adults and embryos. Adult stem cells can be hard to isolate and grow.The use of adult stem cells may prevent transplant rejection.The use of embryonic stem cells raises ethical issuesEmbryonic stem cells are pluripotent and can be grown indefinitely in culture.First, an egg is fertilized by a sperm cell in a petri dish. The egg divides, forming an inner cell mass. These cells are then removed and grown with nutrients. Scientists try to control how the cells specialize by adding or removing certain molecules.
32 Stem CellsThe use of stem cells offers many currently realized and potential benefits.Stem cells are used to treat leukemia and lymphoma.Stem cells may cure disease or replace damaged organs.Stem cells may revolutionize the drug development process.