Given below are two statements : Statement I : The DNA fragments extracted from gel electrophoresis can be used in construction of recombinant DNA. Statement II : Smaller size DNA fragments are observed near anode while larger fragments are found near the wells in an agarose gel. In the light of the above statements, choose the most appropriate answer from the options given below :
Answer: (C) Both statement I and statement II are correct. Answer: (C) Both statement I and statement II are correct Solution: Statement I is correct — DNA bands separated by gel electrophoresis are cut out and eluted from the gel, and these purified fragments are used in constructing recombinant DNA by joining them with cloning vectors.
- A.Statement I is correct but statement II is incorrect
- B.Statement I is incorrect but statement II is correct
- C.Both statement I and statement II are correct✓
- D.Both statement I and statement II are incorrect
Correct Answer
(C) Both statement I and statement II are correct
Solution & Explanation
Answer: (C) Both statement I and statement II are correct Solution: Statement I is correct — DNA bands separated by gel electrophoresis are cut out and eluted from the gel, and these purified fragments are used in constructing recombinant DNA by joining them with cloning vectors. Statement II is correct — DNA is negatively charged and migrates towards the anode; since smaller fragments move farther through the agarose sieving matrix, the smallest fragments are found near the anode while the larger fragments remain near the wells (cathode end). Both statements are true, so (C). NCERT Reference: Ch 9, p.168, line(s) 14 — "Hence, the smaller the fragment size, the farther it moves"