(a) Why is Taq polymerase used instead of ordinary DNA polymerase in polymerase chain reaction (PCR) ? Name the source organism of Taq polymerase.

(b) What is PCR used for ?

(a): In PCR Taq polymerase is used instead of ordinary DNA polymerase because during PCR temperature fluctuates from 80˚c to 72˚c and 54˚c, on such temperature normal DNA polymerase denatures , so we use Taq polymerase.

Taq polymerase is obtained from a species of bacteria, Thermus aquatics.

It is a thermostable enzyme that can withstand high temperature used in denaturation and separation of DNA strands.

(b): PCR - polymerase chain reaction.- is a technique used in molecular biology to create several copies of certain DNA segment.

It is extensively used in the process of gene manipulation.

PCR has multiple uses:

• DNA sequencing

• Genetic mapping

• Genetic fingerprinting at crime scenes

• Tissue typing- before organ transplant to test for compatibility.