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Prokaryotic cell reproductionBinary Fission
Eukaryotic Cell Cycle
Eukaryotic Cell Reproduction: Mitosis & Meiosis
Mitosis: cell reproduction for growth and replacement of cells. This makes identical copies (clones)
Meiosis: cell reproduction for the production of gametes, such as egg and sperm (sex cells)
How many chromosomes in a human cell such as a skin cell?
How many chromosomes in egg and sperm?
Human Karyotype
Is this person male or female?
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MitosisOne division
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46 46
chromosomes
replication
chromatids chromatids
chromosomes
chromosomes chromosomes 23 23 23 23
chromosomesMeiosisTwo divisions
Mitosis: cell reproduction for growth and replacement of cells. This makes identical copies (clones)
What are some examples of mitosis in the body?• Cuts and scrapes• Embryonic growth• Aging• Stomach cells
What are some examples of mitosis in other organisms?• Asexual reproduction (budding and fragmentation)• Plants: growth of roots and stems• Regeneration (starfish arm, lizard tail)
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46 46
MitosisOne division
46
46 46
chromosomes
replication
chromatids chromatids
chromosomes
chromosomes chromosomes 23 23 23 23
chromosomesMeiosisTwo divisions
Sister Chromatids
Chromosome Sister Chromatids
DNA Replication
centromere
Phases in Mitosis
• Interphase: DNA replication• Prophase: chromosomes thicken, nucleus
disappears• Metaphase: chromosomes line up at
center• Anaphase: centromeres split, sister
chromatids separate• Telophase: cytokinesis, division of the
cytoplasm
Applications of Mitosis?
Cancer = abnormalgrowth of cells
Control of the Cell Cycle
MPFis a proteinthat triggersmitosis.
Where is MPFin high amountsand in lowamounts?
Regulation of Cell Cycle
• What controls cell reproduction?• MPF = Maturation Promoting Factor
MPF = cyclin + cdk (cdc2)Protein Kinase = activates other proteinsi.e. spindle fibers that move chromosomes
• Two functions of MPF:1. triggers mitosis2. activates enzymes to breakdown cyclin (negative feedback)
Cancer
• Transformation = process that converts a normal cell to a cancer cell
• Tumor = loss of cell cycle control = abnormal growth of cells
• Benign = noncancerous, Malignant = cancerous
• Metastasis = spread rate of a malignant cancer to locations other than their origin
(tumor cells enter blood vessels and travel to other parts of the body)
Meiosis: cell reproduction for the production of gametes, such as egg and sperm (sex cells)
•Meiosis cuts the number of chromosomes in half
•Meiosis occurs in gonads
•Gonads are reproductive organs (such as ovaries and testes)
•2 divisions1st Meiotic division 2nd Meiotic divisionInterphase Prophase IIProphase I Metaphase IIMetaphase I Anaphase IIAnaphase I Telophase IITelophase I
Homologous Pair (Homologous Chromosomes)
• Chromosomes that carry genes in the same place for the same traits
• One is maternal in origin (from the egg)
• The other is paternal in origin (from the sperm)
Hair colorEye colorSkin tone
hitchikersearlobeswidow’s
1st Meiotic Division
• Interphase: DNA replication
• Prophase I: crossing over
• Metaphase I: independent assortment
• Anaphase I: homologous pairs separate, centromeres intact
• Telophase I: cytokinesis
2nd Meiotic Division
• Prophase II: reorganization, no crossing over
• Metaphase II: chromosomes line up with centromere on line
• Anaphase II: centromere splits, sister chromatids separate
• Telophase II: cytokinesis