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): DNA fragments separated on an agarose gel can be easily visualised under normal visible light. Reason (R): Pure DNA fragments are colourless and require staining with ethidium bromide followed by exposure to UV radiation for visualisation. In the light of the above statements, choose the most appro
Options
- ABoth Assertion and Reason are true and Reason is the correct explanation of Assertion.
- BBoth Assertion and Reason are true but Reason is not the correct explanation of Assertion.
- CAssertion is true but Reason is false.
- DAssertion is false but Reason is true.
Correct answer
D. Assertion is false but Reason is true.
Step-by-step solution
The Assertion is false. Pure DNA fragments are colourless and cannot be seen under normal visible light. The Reason is true. To visualise the separated DNA fragments after gel electrophoresis, the gel must be stained with an intercalating dye like ethidium bromide and then exposed to ultraviolet (UV) radiation. This process reveals the DNA as bright orange bands. Therefore, the Assertion is false but the Reason is true. Answer: Assertion is false but Reason is true.