Question

Primers are

• A. chemically synthesised oligonucleotides that are complementary to the regions of $DNA$
• B. chemically synthesised oligonucleotides that are not complementary to the regions of $DNA$
• C. chemically synthesised, autonomously replicating circular $DNA$ molecules
• D. specific sequences present on recombinant $DNA$

Answer 1

Answer: (A)

Primers are small, 'chemically synthesised oligonucleotides that are complementary to the sequences present at $3^{\prime }$ end of the template $DNA$. They hybridise to the target $DNA$ region, one to each strand of the double helix. These primers are oriented with their ends facing each other allowing synthesis of the $DNA$ towards one another.