Question

During electrophoresis, the band with fragment A travels the same length along the gel as the band with fragment B. The band with fragment A is darker than the band with fragment B. What can you infer from this?

1) Fragment A has a higher molecular weight than fragment B
2) Fragment A has a lower molecular weight than fragment B
3) Fragment A has a higher charge than fragment B
4) Fragment A has a lower charge than fragment B

Answer 1

Fragment A has a higher molecular weight than Fragment B.

Step-by-step explanation:

During electrophoresis, the band with fragment A travels the same length along the gel as the band with fragment B. The band with fragment A is darker than the band with fragment B. From this, we can infer that Fragment A has a higher molecular weight than Fragment B. The darkness of the band indicates a higher concentration of DNA, which is likely due to the larger size of Fragment A.