Question

Which is not one of the elements needed to amplify DNA by polymerase chain reaction (PCR)?

Question 16 options:

	A) Nucleoside triphosphates that serve as the source of the nucleotides A, T, C, and G needed in the synthesis of the new strands of DNA
	B) A restriction endonuclease enzyme that cleaves DNA at specific locations
	C) The segment of DNA that must be copied
	D) A DNA polymerase enzyme that will catalyze the synthesis of a complementary strand of DNA from a template strand
	E) Two primers—short polynucleotides that are complementary to the two ends of the segment to be amplified

Answer 1

Solution: Among all the options provided, Option B which is “A restriction endonuclease enzyme that cleaves DNA at specific location” is not needed to amplify DNA by polymerase chain reaction (PCR). Brief about DNA amplification process: Let us understand the DNA amplification process in details. PCR reaction can generate large amount of copies of specific DNA samples. In the first step of this process, two strands of DNA double helix get physically separated at high temperature in presence of a heat – resistant enzyme DNA polymerase and a buffer solution for optimal activity. (Requires: Option C and D) In the second step, the temperature is lowered and two primers bind with the complementary sequence of separated DNA double helix. This separated DNA helix attached with the primer acts as a template and it is used to assemble new DNA strand from free nucleotides (Source: Deoxynucleoside triphosphates) enzymatically. (Requires: Option A and E) As the reaction progresses, the DNA generated itself can act as a template which is amplified exponentially. Only "Option B” is not involved in PCR process.