Question

Which one is the true statement regarding the DNA polymerase in the process of PCR.
A. It is used to ligate introduced DNA to the recipient cell DNA
B. It serves as the selectable marker
C. It is isolated from a virus.
D. It remains active at high temperature.

Answer 1

PCR is known as polymerase chain reaction. It is widely used in biotechnology and molecular biology to rapidly increase in the number of the DNA from hundreds to the million and billion.It is used in recombinant DNA technology and in different fields of biotechnology and for several tests in criminal cases and so on.

Complete answer:
PCR consists of three steps-Denaturation, annealing and extension. In denaturation two DNA strands are separated at high temperature.In annealing two sets of primers which are complementary to the regions of DNA are introduced. In extension DNA polymerase extends the primer.
1: In the process of PCR the number of DNA increases at a very rapid speed where millions and billions of DNA is formed in at least time. For this rapid process we have to add some enzymes in the reaction.
2: For making the identical strand of the DNA the polymerase enzyme is added to it. The enzyme which is used is known as taq DNA polymerase. It rapid collect the sugar and the
nitrogenous base and add them in sequence to for the identical strand to that of the main
original strand.
3: That taq DNA polymerase is extracted from the bacteria thermus aquaticus which is a broad temperature bacteria and found in hot springs so that it can survive on high temperature.
4: So, the DNA polymerase is also functional on a very high temperature and increase the
number of DNA.
So from the above detail we can say that the true statement about it is that it can remains
active at a very high temperature.

So, the option D is correct.

Note:
DNA ligase enzyme is used to ligate the introduced DNA with the host DNA.
The selectable marker selects the part of DNA from where it has to be cut down and introduced in host DNA.