The image below depicts the result of gel electrophoresis

CBSE Sample Question Paper, Class 12 BIOLOGY Term 2 Question - The image below depicts the result of gel electrophoresis

The image below depicts the result of gel electrophoresis

If the ladder represents sequence length upto 3000 base pairs (bp),
a. Which of the bands (I – IV) correspond to 2500 bp and 100 bp respectively?
b. Explain the basis of this kind of separation and also mention the significance of this process.

Answer.
a. Band III corresponds to 2500 base pairs, and Band IV corresponds to 100bp.
b. The fragments will resolve according to their size. The shorter
sequence fragments would move farthest from well as seen in
Band IV (100 bp) which is lighter as compared to Band III which is
heavier being 2500 base pairs. The significance of electrophoresis is to purify the DNA fragments for use in constructing recombinant DNA by joining them with
cloning vectors.