Question

what can gel electrophoresis help show about dna fragments?
differences in weight
differences in color
differences in temperature
differences in size

Explanation:

Gel electrophoresis is a technique used in molecular biology. DNA fragments are negatively charged. When an electric current is applied in the gel (usually agarose gel), the DNA fragments move through the gel matrix. Smaller DNA fragments move more quickly and farther through the gel pores compared to larger ones. So, gel electrophoresis separates DNA fragments based on their size. Weight is not the determining factor as the movement is more related to size - to - charge ratio (but in a simplified sense for this question, size is the key). DNA fragments do not have inherent color differences that are relevant in this technique, and temperature differences are not what is being shown by gel electrophoresis for DNA fragments.

Answer:

Differences in size