Which of the following statements is NOT correct regarding the linking number?
A)It is a basic parameter characterizing supercoiled DNA. B)L = T + W. C)It is the number of times that 2 strands are intertwined,providing both strands remain covalently intact. D)L = 40 in a relaxed circular DNA duplex of 400 bp.
Which of the following is a characteristic of in vitro DNA synthesis?
A)DNA polymerase adds nucleotides in a 3'?5' direction. B)Correct hydrogen bonding is the primary check of the newly synthesized DNA. C)The primer strand of DNA determines the nucleotides added. D)DNA polymerase copies the template strand of DNA.
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.