The figure below shows three steps (A,B,C) of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents?

Question

Filo · Accepted Answer

The key ingredients of a PCR reaction are Taq polymerase, primers, template DNA, and nucleotides (DNA building blocks). The ingredients are assembled in a tube, along with cofactors needed by the enzyme, and are put through repeated cycles of heating and cooling that allow DNA to be synthesized.

The basic steps are:-

Denaturation (96°C): Heat the reaction strongly to separate, or denature, the DNA strands. This provides single-stranded template for the next step.
Annealing (55 - 65°C): Cool the reaction so the primers can bind to their complementary sequences on the single-stranded template DNA.
Extension (72°C): Raise the reaction temperatures so Taq polymerase extends the primers, synthesizing new strands of DNA.

This cycle repeats 25- 35 times in a typical PCR reaction, which generally takes 22 - 44 hours, depending on the length of the DNA region being copied. If the reaction is efficient (works well), the target region can go from just one or a few copies to billions.

So the correct option is 'C - extension in the presence of heat stable DNA polymerase'.

Question Text	The figure below shows three steps $(A, B, C)$ of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents?
Answer Type	Text solution:1
Upvotes	150

The figure below shows three steps $(A, B, C)$ of Polymerase Chain Reaction (PCR). Select the option giving correct identification together with what it represents?

Text solutionVerified

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