OBJECTIVE LIFE SCIENCE
MOLECULAR BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Cesium fluoride
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Cesium chloride
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Cesium metal
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All of the above
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Detailed explanation-1: -The density gradient centrifugation is the process developed by Matthew Meselson and Franklin Stahl to separate heavy DNA with N15 from DNA, for providing evidence for semi-conservative replication of DNA. In their experiment, they used the bacteria E. coli as a model system.
Detailed explanation-2: -(i) Meselson & stahl used cesium chloride density gradient to distinguish heavy DNA molecules from the normal DNA molecules.
Detailed explanation-3: -Under high centrifugal force, a solution of cesium chloride (CsCl) molecules will dissociate. The heavy Cs+atoms will be forced away from the center towards the outer end of the tube, but will at the same time diffuseback towards the top of the tube, thus forming a shallow density gradient.
Detailed explanation-4: -Matthew Meselson, Franklin Stahl, and Jerome Vinograd, developed cesium chloride, or CsCl, density gradient centrifugation in the 1950s at the California Institute of Technology, or Caltech, in Pasadena, California.