NEET2026BiologyChapterActual
A mixture containing DNA fragments of sizes 150 bp , 450 bp , 900 bp , and 2500 bp is subjected to agarose gel electrophoresis. Which of these fragments will be found closest to the anode after the run is completed?
Options
- AThe 2500 bp fragment
- BThe 900 bp fragment
- CThe 450 bp fragment
- DThe 150 bp fragment
Correct answer
D. The 150 bp fragment
Step-by-step solution
In agarose gel electrophoresis, DNA fragments are separated based on their size. Since DNA molecules are negatively charged, they migrate towards the positive electrode (anode) under an electric field. The agarose gel acts as a sieve, allowing smaller DNA fragments to move faster and further through the pores of the gel matrix compared to larger fragments. Among the given fragments of sizes 150 bp , 450 bp , 900 bp , and 2500 bp , the 150 bp fragment is the smallest. Therefore, it will travel the maximum distance a