presentation stem cells

7/31/2019 Presentation Stem Cells

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MADE BY: BHARTI PANT

STUDENT: CLASS XI B

KENDRIYA VIDHYALAY(IMA)


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Stem cells are biological cells found in allmulticellular organisms, thatcan divide (through mitosis)

and differentiate into diverse specialized celltypes and can self-renew to produce more stemcells. In mammals, there are two broad types ofstem cells: embryonic stem cells, which are

isolated from the inner cell mass of blastocysts,and adult stem cells, which are found invarious tissues. In adult organisms, stem cellsand progenitor cells act as a repair system forthe body, replenishing adult tissues


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Research into stem cells grew out of findingsby Ernest A. McCulloch and James E. Till atthe University of Toronto in the 1960s


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The classical definition of a stem cell requires thatit possess two properties:

Self-renewal: the ability to go throughnumerous cycles of cell division while maintainingthe undifferentiated state.

Potency: the capacity to differentiate intospecialized cell types. In the strictest sense, thisrequires stem cells to be

either totipotent or pluripotent

to be able to giverise to any mature cell type,although multipotent or unipotent progenitorcells are sometimes referred to as stem cells.


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stem cells can differentiate into embryonic andextra embryonic cell types. Such cells canconstruct a complete, viable organism. These

cells are produced from the fusion of an eggand sperm cell. Cells produced by the first fewdivisions of the fertilized egg are alsototipotent


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Pluripotent stem cells are the descendants oftotipotent cells and can differentiate into nearlyall . cells derived from any of the three germ

layers


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Multipotent stem cells can differentiate into anumber of cells, but only those of a closelyrelated family of cells.


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Oligopotent stem cells can differentiate intoonly a few cells, such as lymphoid or myeloidstem cells


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Unipotent cells can produce only one cell type,their own,but have the property of self-renewal, which distinguishes them from non-

stem cells (e.g., muscle stem cells).


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Medical researchers believe that stem celltherapy has the potential to dramaticallychange the treatment of human disease. A

number of adult stem cell therapies alreadyexist, particularly bone marrowtransplants that are used to treat leukemia.


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In the future, medical researchers anticipatebeing able to use technologies derived fromstem cell research to treat a wider variety of

diseases including cancer ,Parkinson'sdisease, spinal cord injuries, Amyotrophiclateral sclerosis, multiple sclerosis,and muscle damage, amongst a number of

other impairments and conditions


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1908: The term "stem cell" was proposed forscientific use bythe Russian histologist Alexander

Maksimov (18741928) at congress of

hematologic society in Berlin. It postulatedexistence of hematopoietic stem cells.

1963: McCulloch and Till illustrate the presence

of self-renewing cells in mouse bone marrow


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1992: Neural stem cells are cultured in vitro asneurospheres.

January 2008: Development of human cloned

blastocysts following somatic cell nucleartransfer with adult fibroblasts.

30 October 2008: Embryonic-like stem cellsfrom a single human hair.

11 October 2010 :First trial of embryonic stemcells in humans


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1.) Google.

2.)Wikipedia(http://en.wikipedia.org/wiki/St

em_cell)

3.)^"New Stem-Cell Procedure Doesn't Harm

Embryos, Company Claims". Fox News. 2006-08-24. Retrieved 2010-02-28.
http://en.wikipedia.org/wiki/Stem_cellhttp://en.wikipedia.org/wiki/Stem_cellhttp://en.wikipedia.org/wiki/Stem_cellhttp://www.foxnews.com/story/0,2933,210078,00.htmlhttp://www.foxnews.com/story/0,2933,210078,00.htmlhttp://www.foxnews.com/story/0,2933,210078,00.htmlhttp://www.foxnews.com/story/0,2933,210078,00.htmlhttp://www.foxnews.com/story/0,2933,210078,00.htmlhttp://www.foxnews.com/story/0,2933,210078,00.htmlhttp://en.wikipedia.org/wiki/Stem_cellhttp://en.wikipedia.org/wiki/Stem_cellhttp://en.wikipedia.org/wiki/Stem_cell


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THANK YOU

presentation stem cells

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