A mixture containing DNA fragments a, b, c and d with molecular weights of a + b = c, a > b and d > c, was subjected to agarose gel electrophoresis. The positions of these fragments from cathode to anode sides of the gel would be (1) b, a, c, d (2) a, b, c, d (3) c, b, a, d (4) b, a, d, c
I think the options given by you are not correct. Kindly, check them and then do get back to us.
Its true that movement of DNA fragments takes place from cathode( negative electrode) towards anode(positive electrode) in gel electrophoresis as DNA is negatively charged molecule.
DNA fragments of lower molecular weight move farther than higher molecular weight fragments. So, the correct answer is d-c-a-b order from cathode to anode according to given conditions in the question.