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1/31/12. Objectives Structure v. function connection Stem cells primer Do now: Assemble in three or four groups of 2-3 students Do later: Catch up on missing work (RRQ 1-5, mitosis picture, organelle picture, organelle quiz , plasmolysis lab, etc.). Diversity of Cells.
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1/31/12 • Objectives • Structure v. function connection • Stem cells primer • Do now: Assemble in three or four groups of 2-3 students • Do later: Catch up on missing work (RRQ 1-5, mitosis picture, organelle picture, organelle quiz, plasmolysis lab, etc.)
Diversity of Cells • In groups, answer the following 4 questions about your type of cell: • What is the function of this cell? • How does this cell perform its function? • What is unique about the structure of this cell? • How does the cell’s structure enable it to perform its function?
Diversity of Cells • Over 250 specialized cell types in our bodies. • Where do they come from? • Stem cells
Stem cells • Stem cells are “blank cells” that have the ability to produce one or more types of specialized cells.
Stem cells • Differentiation is the process by which a stem cell produces a more specializedcell.
Differentiation • How does differentiation occur? • All cells have a full set of DNA • Instructions to make our whole body • As stem cells differentiate, many genes get “turned off,” except for the genes needed to make that differentiated cell. DNA – “switched on” DNA – “switched off”
Embryonic Stem Cell Research • Embryos have stem cells that can produce all adult cells. • Research application • Watch how ESCs grow to learn about human development
Stem Cells • Four different levels of stem cells • Totipotent – can produce all adult cells & placenta • Pluripotent – can produce all adult cells (not placenta) • Multipotent – can produce related families of cells • E.g. hematopoietic stem cells blood • Unipotent – can produce one kind of cell • E.g. liver cells, hair cells
Induced Pluripotent Stem Cells • 2008 – Successful conversion of adult cells back into pluripotent stem cells • Potential to re-grow your own tissues and organs