On earth, energy? a.) cycles back and fourth through many systems. b.) comes in as light and leaves as heat. c.) comes in as heat and leaves as as light. d.) is constantly destroyed and must be regenerated.

the dna molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. power is turned on and dna fragments migrate through gel (towards the positive electrode).

explanation:

idk im sorry.

answer; ///(a) ;