Question

Who discovered PCR (polymerase chain reaction)?
A) Wilmut
B) A.Jeffreys
C) Einthoven
D) Kary Mullis

Answer 1

Polymerase chain reaction or PCR is used to make multiple copies of a DNA segment. It is a common laboratory and clinical technique which depends upon thermal cycling. Reactants are exposed to repeated cycles of heating and cooling.

Complete answer:
In this in vitro technique used to amplify many double-stranded DNA molecules of identical size and same sequence using enzymatic reactions.
Condition and steps of PCR:- Denaturation of DNA template.
Annealing of primers.
Extension of DNA molecules.
Chemical components of PCR

Magnesium chloride
Buffer with pH- 8.3-8.8
DNA Polymerase enzyme
Target DNA
Applications of PCR
HIV- 1, Neisseria gonorrhoeae, Forensic testing, Molecular identification, DNA Fingerprinting, Detection of pathogens, Drug discovery, Mutation screening, Bioinformatics, Gene expression studies, Site directed mutagenesis.
Advantages of PCR
Result oriented.
DNA is required in small amounts.
Very fast result within 1 day.
Easily detect point mutations.
More precise technique.

Einthoven- In 1895 he invented the first electrocardiogram (ECG). He received the Nobel Prize in Physiology.
Wilmut- English biologist, embryologist best known for the leader of a research group.

So, the correct answer will be option D i.e, Kary Mullis.
Note: Two main reagents of PCR are:-single strand DNA fragments called oligonucleotides which are the complementary sequence to target DNA region and a DNA polymerase like Taq polymerase and the enzyme should be heat stable to avoid its denaturation under high temperature.