Question

In gel electrophoresis DNA molecules migrate from _____ to _____ ends of the gel.

a, acidic ... basic
b, negative ... positive
c, basic ... acidic
d, long ... short
e, positive ... negative

Answer 1

DNA molecules migrate from the negative to the positive end of a gel in gel electrophoresis due to their negative charge.

Step-by-step explanation:

In gel electrophoresis, DNA molecules migrate from the negative to the positive ends of the gel due to the net negative charge of the phosphate groups in the DNA backbone. This technique separates DNA fragments based on size - smaller molecules navigate through the gel's pores faster than larger ones. Consequently, the correct answer to the student's question is that DNA molecules migrate from negative to positive ends of the gel, which corresponds to option b.

Answer 2

b, negative ... positive

Step-by-step explanation:

Gel electrophoresis is a method used in molecular biology for DNA analysis. This method includes the separation of DNA fragments through the gel according to their size or shape under the influence of aplid electric current. Since the fragments of DNA are negatively charged, they will move from negative to positive end.

Small fragments will move faster than larger ones.

One of the major source of error is contamination of the DNA sample. This refers to the presence of foreign DNA in the sample of interest. As a consequence, the gel will have more bands.

Another errors might appear as a result of wrong concentration of the gel, wrong buffer pH, high/low concentration of dye etc.