1. The enzyme responsible for initiating the unwinding of double-stranded DNA (eliminating supercoiling) by nicking a single strand of the DNA molecule is :   Gyrase   Helicase   Topoisomerase   Ligase   Hint Half-n-half Clue   2. Because DNA polymerase III can only act from 5' to 3', continuous strand growth can be achieved only along one of the template strands (Leading strand) and strand growth along the other strand must occur discontinuously resulting in the production of a series of short sections of new DNA called :   Replicon fragments   Okazaki fragments   Klenow fragments   None of the above   Half-n-half Clue   3. An enzyme that recognizes and cuts DNA only at a particular sequence of nucleotides is often called :   Restriction endonuclease   RNA polymerase   Photolyase   DNA glycosylase   Half-n-half Clue   4. The enzyme that stitches Okazaki fragments together (along the lagging strand) is called :   DNA Ligase   Holoenzyme   DNA Polymerase II   Topoisomerase   Half-n-half Clue   5. A mamalian cell typically has 1.2 meters (when completely outstretched) of double stranded DNA.The total time to duplicate the DNA is 5 hours. How many origins of replication are there if the rate of duplication is 16µmeters/min ?   250   15000   1   500   Half-n-half Clue   6. What does transformation involve in Bacteria ?   the creation of a strand of DNA from RNA   the creation of a strand of RNA from DNA   assimilation of external DNA into a cell   the infection of cells by a phage DNA molecule   Half-n-half Clue   7. DNA Polymerase III is actually an aggregate of several different protein subunits. So it is often called a :   Holoenzyme   Primeosome   replisome   None of the above   Half-n-half Clue