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Expert: Florence M Rollwagen - 8/25/2008


Question
Hello Sir..
         As cells are similar of different tissues of the body, how do they perform different functions? I mean to say their basic structure is same so how can they function differently?

Answer
Hi again, Pooja:  It's true that cells have many of the same structures: membrane, mitochondria, nucleus.  The differences in function lie in their genetic code.  All cells have the same genetic code, but control of gene expression gives the cell it's specificity.  For example, a pancreas cell and a cornea cell both have the same DNA.  But the pancreas cell expresses the gene(s) for insulin, while the eye cell expresses the gene(s) for crystallin(lens material).  

An excellent example of gene control lies in the lactose operon, a control mechanism which won its discoverers the Nobel Prize (Jacob and Monod).  Here is a website that I use in my classes.  Look in the left hand column and click on "lac operon" for a great video on control of cell functions.

http://vcell.ndsu.nodak.edu/animations/

I hope this answer has helped you.  Please write back if you have more questions.

FM Rollwagen, PhD

Biology

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Florence M Rollwagen

Expertise

I can answer questions in biology, microbiology and immunology on the undergraduate or graduate level. I can also address medical and health concerns regarding alternative medicine, autoimmune diseases (lupus, MS) liver disease and intestinal problems.

Experience

I have over 20 years experience in research and teaching at the medical/graduate level, and 5 years teaching college biology and microbiology. My expertise is in microbiology and immunology, specifically the biology of cytokines and soluble immune response modifiers. I also carried out original research in blood substitutes and shock/trauma.

Organizations
American Association of Immunologists (AAI) American Association for the Advancement of Science (AAAS)

Publications
Journal of Experimental Medicine, Journal of Immunology, Cytokine, Shock, Experimental Hematology

Education/Credentials
BS biology 1966 MS biology 1968 PhD immunology 1979

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