Question

In the first step of PCR technique heating breaks the .......... bonds of DNA molecule.

• A. hydrogen
• B. phospho-di-ester
• C. glycosidic
• D. sugar-phosphate

Hint:

The first step of PCR involves breaking hydrogen bonds between DNA strands to allow for amplification.

Answer 1

The Correct Option is A

Step 1: Understanding PCR technique.
Polymerase Chain Reaction (PCR) is a method used to amplify DNA. The first step of PCR involves heating the DNA to separate the strands. This process breaks the hydrogen bonds between the complementary base pairs in the double-stranded DNA.
Step 2: Analyzing the options.
(A) hydrogen: Correct — The heating step in PCR breaks the hydrogen bonds between the base pairs of the DNA, allowing the strands to separate.
(B) phospho-di-ester: The phosphodiester bonds hold the sugar-phosphate backbone together and are not broken during the heating step of PCR.
(C) glycosidic: Glycosidic bonds link sugars to bases, but they are not involved in the separation of DNA strands during PCR.
(D) sugar-phosphate: The sugar-phosphate bonds form the backbone of the DNA molecule, and they are not broken during the initial heating of PCR.
Step 3: Conclusion.
The correct answer is (A) hydrogen, as heating during PCR breaks the hydrogen bonds between the complementary base pairs of DNA.