How does gel electrophoresis sort strands of DNA?l

Gel Electrophoresis is a way to sort and measure the DNA strands. Scientists use the technique whenever they need to sort DNA strands according to lengths, this is because it helps them determine patterns, banding patterns create a unique fingerprint for a certain individual. During the process, the shorter strands move faster because they have less mass compared to the longer strand. Therefore, the short strands end up farther away from the starting point than the longer strands, which is how the difference in lengths sort themselves out.

true, i don't really know what you're asking but from the info you provided im guessing the answer is true.

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?