Assume That You Grew a Culture of E

question 22

Essay

Assume that you grew a culture of E.coli for many generations in medium containing ¹⁵N (from the ammonium ion),a heavy isotope of nitrogen.You extract DNA from a portion of the culture and determine its density to be 1.723 gm/cm³ (call this sampleA).You then wash the remaining E.coli cells and grow them for one generation in ¹⁴N,extract the DNA from a portion of the culture,and determine its density to be 1.715 gm/cm³ (call this sampleB).You let the culture grow for one more generation in ¹⁴N and extract the DNA (call this sampleC)Each sample of DNA (A,B,and C)is then heated to completely denature the double-stranded structures,cooled quickly (to keep the strands separate),and subjected to ultracentrifugation.Present the centrifugation profiles for heat-denatured DNA (samples A,B,andC)that you would expect.Use the graph below.(Note: Although not the case,assume that single-stranded DNA has the same density as double-stranded DNA.)

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Definitions:

Federal District Court

is a general trial court of the United States federal court system that has both original jurisdiction over federal cases and questions involving federal law.

Removal

The act of transferring a case from one court to another, typically from a state court to a federal court in the legal context.

Nerve Center

The core location or facility from which the control and coordination of activities are directed, often used in the context of business operations or network operations.

Subject-Matter Jurisdiction

The power of a court to adjudicate cases of a certain nature or those pertaining to a specified subject area.