Question 3

(Multiple Choice)

An intact 4 kb plasmid has a 50% G+C content,and a 4 kb fragment of E.coli chromosomal DNA has a 55% G+C content.Which of the following is NOT correct when comparing the two?


A)The Tm of the plasmid would be less than the Tm of the chromosomal DNA.
B)The c0t1/2 value (time required to renature 50% of the DNA molecules)of the plasmid would be more than that of the chromosomal DNA.
C)The plasmid DNA and chromosomal DNA would both show approximately a 30%-40% increase in their absorption at 260 nm upon heating to 90°C.
D)The plasmid DNA would contain more negative supercoiling than the chromosomal DNA fragments.

Answer

B