Which one of the followings is not a step in amplification of gene of interest using PCR?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Somatic hybridisation
PCR copies a chosen piece of DNA again and again. Each cycle has three steps: denaturation, primer annealing and extension.
Option (1) Somatic hybridisation — Not a step of PCR. It is the fusion of protoplasts of two different plants to make a hybrid (e.g. pomato); it has nothing to do with copying DNA.
Option (2) Denaturation — A step of PCR.
Option (3) Extension — A step of PCR.
Option (4) Annealing — A step of PCR.
NCERT Extract:
Amplification of Gene of Interest using PCR – “PCR stands for Polymerase Chain Reaction. In this reaction, multiple copies of the gene (or DNA) of interest is synthesised in vitro using two sets of primers (small chemically synthesised oligonucleotides that are complementary to the regions of DNA) and the enzyme DNA polymerase. The enzyme extends the primers using the nucleotides provided in the reaction and the genomic DNA as template. If the process of replication of DNA is repeated many times, the segment of DNA can be amplified to approximately billion times, i.e., 1 billion copies are made.”
