Question

Question 11

0 / 1 point

The 2009 Nobel Prize in Physiology and Medicine was awarded for the discovery of what type of enzyme that is needed to replicate chromosome ends?

Question options:

	A DNA-dependent DNA polymerase
	A RNA-dependent DNA polymerase
	A DNA-dependent RNA polymerase
	A RNA-dependent RNA polymerase

Question 12

0 / 1 point

In the presence of fluoroquinolone drugs, sensitive bacteria accumulate double stranded DNA breaks. Why?

Question options:

	Fluoroquinolones prevent DNA ligase from joining Okazaki fragments
	Fluoroquinolones prevent telomerase from extending DNA ends
	Fluoroquinolones prevent RecBCD from initiating recombinational DNA repair.
	Fluoroquinolones prevent topoisomerase I from re-joining DNA after the enzyme cleaves both strands.
	Fluoroquinolones prevent topoisomerase II from re-joining DNA after the enzyme cleaves both strands.

Question 13

0 / 1 point

You are analyzing the products of a topoisomerase I-catalyzed reaction using agarose gel electrophoresis. In the first lane you load the supercoiled plasmid substrate only. In the second lane, you load substrate DNA that was incubated with topo I in the absence in of ATP. In the third lane you load the substrate DNA that was incubated with topo I in the presence of ATP. How would you expect the DNA to migrate on the gel?

Question options:

	The DNA in lane 1 will migrate slower than either DNA in lane 2 or 3.
	The DNA in lane 2 will migrate slower than either DNA in lane 2 or 3.
	The DNA in lane 3 will migrate slower than either DNA in lane 2 or 3.
	The DNA in lane 2 will migrate faster than either DNA in lane 2 or 3.
	The DNA in lane 1 will migrate faster than either DNA in lane 2 or 3.

Answer 1

11.
The 2009 Nobel Prize in Physiology and Medicine was awarded for the discovery of the enzyme that is needed to replicate chromosome ends namely telomerase.
It is an RNA dependent DNA polymerase. It synthesizes DNA using RNA as template.

12.
Quinolones are the molecules which trap type 2 topoisomerases in bacteria. As a result, it causes many
DNA break containing complexes in the chromosomes.
OPtion e is the correct answer.

13.
Topoisomerase 1 is an enzyme used for removing supercoils or to break strands in the recombination process.
These need ATP to function.
Given that n the first lane you load the supercoiled plasmid substrate only. In the second lane, you load substrate DNA that was incubated with topo I in the absence in of ATP. In the third lane, you load the substrate DNA that was incubated with topo I in the presence of ATP.
So lane 3 have broken strands which can migrate faster than DNA in lane 1 and 2.
So option c is the answer.