Question

Primers are

• A. chemically synthesised oligonucleotides to which Taq polymerase adds deoxyribonucleotides on its 5' end
• B. chemically synthesised oligonucleotides that are complementary to specific regions of template DNA
• C. chemically synthesised, autonomously replicating circular DNA molecules
• D. sequences present in the genes of our interest

Answer 1

The correct option is B chemically synthesised oligonucleotides that are complementary to specific regions of template DNA

Primers are small, chemically synthesised oligonucleotides that are complementary to the DNA sequence for which they have been designed for. They anneal to the target DNA region, one to each strand of the double helix. They present a free 3' OH end onto which new dNTPs can be added by polymerase.

They are not self replicating, as they do not have an ori - origin of replication.

Genes are the segments of DNA which get transcribed to form mRNA. The mRNA gets translated to produce the desired product. Gene can be extracted out and cloned to get the product on a large scale.