Recent Changes

Wednesday, October 3

  1. page Modification of Genes and Proteins edited ... and ProteinsBy Joshua Pikovsky, Paul Southard, Joshua, Paul, and Jake Secor {http://www…
    ...
    and ProteinsBy Joshua Pikovsky, Paul Southard,Joshua, Paul, and Jake Secor
    {http://www.jonbarron.org/sites/default/files/images/protein_molecule1.jpg}
    {Modification of Genes and Proteins.pptx}
    (view changes)
    3:34 pm

Thursday, March 22

  1. page Creating variation edited ... Meiosis is a process which converts diploid cells to haploid gametes and which causes a change…
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    Meiosis is a process which converts diploid cells to haploid gametes and which causes a change in the genetic information of those cells to create diversity in the offspring.
    (3)
    {chromosomes-haploid_-and-diploid.gif} (1)
    Above is an example of a chromosome from a haploid cell and a chromosome from a diploid cell. A
    A haploid cell
    {Fission.jpg} (2)
    Asexual reproduction lacks the mechanism of meiosis, and there is therefore no genetic diversity created in that process. The oversimplified diagram above
    (view changes)
    7:23 pm
  2. page How Do Cells Differentiate? edited ... b) How does the stem cell position and function like it's neighboring cells? (10 pt) Answer…
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    b) How does the stem cell position and function like it's neighboring cells?
    (10 pt)
    Answer Key:
    a) (6 points)
    Differences in DNA
    Stem cell DNA is more loosely wrapped around histones, or muscle cell DNA is more tightly wrapped around histones (1 pt.)
    Muscle cell's DNA is structure to prevent unnecessary genes to be present (1 pt)
    Characteristics of Totipotent Stem Cells
    Can form any cell in the body and an individual if separated (1 pt)
    Has the same basic DNA as the Muscle cell (1 pt)
    DNA modifications of the Muscle Cell
    DNA Methylation adds a methyl group to the DNA; must mention cellular memory, or enhancing or inhibiting gene expression (1 pt)
    Histones modification; must mention cellular memory, or enhancing or inhibiting gene expression (1 pt)
    b) (6 points)
    Mention of Drosophilia (1 pt.)
    Cells position themselves on finer and finer scale to establish correct position (1 pt.)
    Muscle tissue environment would influence stem cell (1 pt.)
    Definition and Mention of Cytoplasmic Determinants (1 pt.)
    Differentiation of Totipotent stem cell to mesodermal stem cell (1 pt.)
    MyoD differentiates cell to a muscle cell (1 pt.)

    Questions:
    1. What is the initial cause of differentiation during development?
    (view changes)
    10:23 am
  3. page How Do Cells Differentiate? edited http://www.stanford.edu/group/nusselab/cgi-bin/wnt/ How Do Cells Differentiate? By: Melissa Mul…
    http://www.stanford.edu/group/nusselab/cgi-bin/wnt/
    How Do Cells Differentiate?
    By: Melissa Mulvany, Azman Rashid, Michael Schanz
    ...
    The IQ-1 molecule uses signaling pathways within the organism to control how the stem cells develop. The IQ-1 molecule functions in the way that is explained above, but it uses cell signaling pathways to work this way. While it inhibits coactivator p300, it also blocks one arm of a signaling pathway called the Wnt pathway, while increasing the strength of the signal from the other arm of the Wnt pathway. This signaling pathway has two effects on stem cells; a proliferative effect and a differentiative effect. More simply, it has one effect that increases the size of the cell, and another effect that causes the cell to actually differentiate. The IQ-1 molecule is the major signaling molecule of stem cells, it's the molecule that is responsible for actually signaling for the cell to keep dividing. (6)
    The Wnt pathway is formed of Wnt proteins, and much of what we know about the Wnt pathway has been discovered while studying Drosophila. This pathway is the main pathway used for cell signaling during embryogenesis and up until the cell differentiates. Many developmental defects are a result of a mutation of Wnt proteins, or abnormal signaling along the Wnt pathway. (19)
    {wnt_pathway.gif}
    (20)

    The Role of Proteins in the Differentiation of Somatic Cells:
    Muscle cells:
    ...
    Information on development of embryonic stem cells (18)
    Information on the Wnt pathway (19)
    Wnt picture (20)
    (view changes)
    3:35 am
  4. file wnt_pathway.gif uploaded
    3:33 am
  5. page How Do Cells Differentiate? edited ... How Cell Signaling is Involved in Stem Cell Development: The IQ-1 molecule uses signaling pat…
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    How Cell Signaling is Involved in Stem Cell Development:
    The IQ-1 molecule uses signaling pathways within the organism to control how the stem cells develop. The IQ-1 molecule functions in the way that is explained above, but it uses cell signaling pathways to work this way. While it inhibits coactivator p300, it also blocks one arm of a signaling pathway called the Wnt pathway, while increasing the strength of the signal from the other arm of the Wnt pathway. This signaling pathway has two effects on stem cells; a proliferative effect and a differentiative effect. More simply, it has one effect that increases the size of the cell, and another effect that causes the cell to actually differentiate. The IQ-1 molecule is the major signaling molecule of stem cells, it's the molecule that is responsible for actually signaling for the cell to keep dividing. (6)
    The Wnt pathway is formed of Wnt proteins, and much of what we know about the Wnt pathway has been discovered while studying Drosophila. This pathway is the main pathway used for cell signaling during embryogenesis and up until the cell differentiates. Many developmental defects are a result of a mutation of Wnt proteins, or abnormal signaling along the Wnt pathway. (19)
    The Role of Proteins in the Differentiation of Somatic Cells:
    Muscle cells:
    ...
    Campbell, Neil A., and Jane B. Reece. "The Genetic Bases of Development." Biology. Vol. 6. San Francisco: Benjamin Cummings, 2002. Print. (17)
    Information on development of embryonic stem cells (18)
    Information on the Wnt pathway (19)
    (view changes)
    3:26 am
  6. page How Do Cells Differentiate? edited ... The Role of Proteins in the Differentiation of Somatic Cells: Muscle cells: ... cells (17)…
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    The Role of Proteins in the Differentiation of Somatic Cells:
    Muscle cells:
    ...
    cells (17). An embryonic precursor cell, a unipotent cell, creates MyoD from the master control gene. The MyoD would be an internal signal to increase the rate of transcription in another part of the DNA. More Transcription factors would be produced as a result of MyoD. The factors would increase the rate of muscle-related protein production. This process would transform the precursor cell to a myoblast, a determined muscle cell.
    {Screen_Shot_2012-03-12_at_12.05.56_AM.jpg} (17)
    Liver cells:
    ...
    division. However, the picture from the Journal
    ...
    Biological Chemistry differentiates between hepatocytes andbelieves that haematopoietic stem cells. According to CSU, theycells are used in the same cell.differentiation process. The Journal
    {http://www.healthjockey.com/images/liver-regeneration.jpg} Diagram of Liver Regeneration(9)
    Neurons:
    ...
    β-catenin controls skin stem cell differentiation to allow the cell to differentiate into follicular keratinocytes, cells forming the protective barrier of the skin from the outside environment. Without the protein, the cell becomes a regular epidermal cell in the skin. (13)
    {http://upload.wikimedia.org/wikipedia/commons/8/84/Epidermis-delimited.JPG} (14)
    A final video
    Essay:
    A Embryonic Totipotent Stem Cell is inserted to the human muscle.
    ...
    E) None of the above
    Sources:
    http://www.google.com/imgres?um=1&hl=en&sa=X&biw=1280&bih=699&tbm=isch&tbnid=3Fj2eyIPp6quhM:&imgrefurl=http://www.drexelmed.edu/Home/AboutOurFaculty/ItzhakFischer.aspx&docid=mOJREhM1rK93aM&imgurl=http://www.drexelmed.edu/Portals/0/neurobiology/lg/differentiation.jpg&w=323&h=324&ei=LwddT7ntGebd0QGsoKiqDw&zoom=1&iact=hc&vpx=352&vpy=142&dur=7498&hovh=225&hovw=224&tx=141&ty=128&sig=107641645611141032700&page=1&tbnh=145&tbnw=145&start=0&ndsp=18&ved=1t:429,r:1,s:09Neural stem cell picture (5)
    Information on IQ-1 molecules -(6)
    http://www.miracleofthebloodandheart.com/2_clip_image005_0000.jpgBlood cell picture from stem cell
    http://www.pathologyoutlines.com/images/marrow/001.jpg - Pluripotent Stem Cell Differentiation photo (8)
    http://www.vivo.colostate.edu/hbooks/pathphys/digestion/liver/regen.htmlRegeneration of the liver (9)
    http://learn.genetics.utah.edu/content/tech/stemcells/ips/ - Histones and DNA photo and information on Stem cell DNA structure (10)
    http://jbiol.com/content/8/8/70 - Information on stem cell renewal (11)
    http://www.nature.com/scitable/topicpage/cell-differentiation-and-tissue-14046412 - information on stem cell differentiation (12)
    http://www.cell.com/retrieve/pii/S0092867401003361?cc=yβ-Catenin and stem cell differentiation in skin (13)
    http://upload.wikimedia.org/wikipedia/commons/8/84/Epidermis-delimited.JPG

    Eipidermis picture
    (14)
    The video on cell differentiation - (15)
    http://www.nature.com/scitable/content/ne0000/ne0000/ne0000/ne0000/14707620/U2CP3-4B_RegulProteinsLoop_ksm.jpg - picture of Obligatory asymmetric replication (16)
    (view changes)
    3:18 am

Wednesday, March 21

  1. page creating a plan for the body edited Creating a Body Planby Matthew Bogen, Rachael Judson, Christine Muise {Body Plan Presentation-3.p…
    Creating a Body Planby Matthew Bogen, Rachael Judson, Christine Muise
    {Body Plan Presentation-3.pptx}Presentation-3.ppt}
    There are genes in the body that control the where certain cells form, and they act as an on and off switch for other cells' genes. Pattern formation is a basic example. These genes are able to use spatial organization to form a body of everything from a fly to a mouse to a human being.
    Fate maps are a way to track cells as they become more specialized in the body. A German scientist Walther Vogt used this to form the foundation of how germ layers lead to different specialized parts of the body and there use in the embryo. The use of C. Elegans, in research has allowed scientists to draw a fate map for a fully formed nematode. Because of the relatively small size and amount of cells - 959 - scientists are able to watch the cells form and track them, allowing a better understanding of specialized tissue formation. It helps show the loss of cells' ability to be totipontent, or specialize into any kind of cell.(11)
    (view changes)
    10:20 pm

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