Question

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

Answer 1

Hint: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.