In a molecular biology laboratory, a student performs gel electrophoresis to separate DNA fragments of various sizes. Which of the following statements correctly explains the mechanism of this separation?
DNA carries a positive charge and moves towards the cathode (negative electrode), with smaller fragments moving faster than larger ones due to less resistance from the gel matrix.
DNA carries a negative charge and moves towards the anode (positive electrode), with smaller fragments moving faster than larger ones because they can more easily navigate the pores of the gel.
DNA carries a negative charge and moves towards the anode (positive electrode), with larger fragments moving faster than smaller ones because they experience a stronger electrical pull.
DNA carries a positive charge and moves towards the cathode (negative electrode), with larger fragments moving faster than smaller ones due to their greater momentum.
