NEETZoologyBiotechnology - Principles and Processes
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The process of elution is essential for isolating purified DNA fragments from an agarose gel for recombinant DNA construction. Reason (R): DNA fragments separated on the gel can only be visualised after staining with ethidium bromide and exposure to UV radiation. In the light of the above statement
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- BAssertion (A) is true but Reason (R) is false.
- CAssertion (A) is false but Reason (R) is true.
- DBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
Correct answer
D. Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
Step-by-step solution
Assertion (A) is true because the separated bands of DNA are cut out from the agarose gel and extracted from the gel piece. This step, known as elution, is necessary to obtain purified DNA fragments for constructing recombinant DNA by joining them with cloning vectors. Reason (R) is also true because DNA fragments cannot be seen in visible light; they must be stained with ethidium bromide followed by exposure to UV radiation to be visualised as bright orange bands. However, Reason (R) is not the correct explanation