NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Biology
- Chapter
- Chapter
NEET 2026 · Biology · Chapter
In the Polymerase Chain Reaction (PCR) technique, which of the...
In the Polymerase Chain Reaction (PCR) technique, which of the following events specifically occurs during the annealing step?
Options
- ABreaking of hydrogen bonds to separate the double-stranded DNA template
- BHybridization of two sets of primers to the complementary regions of the DNA
- CPolymerization of deoxynucleotides by a thermostable DNA polymerase
- DJoining of amplified DNA fragments using the enzyme DNA ligase
Correct answer
B. Hybridization of two sets of primers to the complementary regions of the DNA
Step-by-step solution
The Polymerase Chain Reaction (PCR) involves three main steps:
1. Denaturation: The double-stranded DNA is heated to a high temperature to break the hydrogen bonds, resulting in single-stranded DNA.
2. Annealing: The temperature is lowered to allow two sets of primers to hybridize (bind) to their complementary sequences on the single-stranded DNA templates.
3. Extension: A thermostable DNA polymerase (such as Taq polymerase) synthesizes the new DNA strand by adding deoxynucleotides to the primers.
Therefore, the hybridization of primers to the complementary regions of the DNA occurs specifically during the annealing step.
Answer: Hybridization of two sets of primers to the complementary regions of the DNA
1. Denaturation: The double-stranded DNA is heated to a high temperature to break the hydrogen bonds, resulting in single-stranded DNA.
2. Annealing: The temperature is lowered to allow two sets of primers to hybridize (bind) to their complementary sequences on the single-stranded DNA templates.
3. Extension: A thermostable DNA polymerase (such as Taq polymerase) synthesizes the new DNA strand by adding deoxynucleotides to the primers.
Therefore, the hybridization of primers to the complementary regions of the DNA occurs specifically during the annealing step.
Answer: Hybridization of two sets of primers to the complementary regions of the DNA