What happens to DNA when placed into an aqueous solution at physiological pH?
A)individual DNA molecules attract each other due to presence of positive and negative charges
B)individual DNA molecules repel each other due to presence of negative charges
C)individual DNA molecules repel each other due to presence of positive charges
D)DNA molecules bind to negatively charged proteins
E)none of the above

Question

Quizplus · Accepted Answer

DNA has a negatively charged phosphate backbone, which results in individual DNA molecules repelling each other when placed in an aqueous solution at physiological pH. This is because water molecules, which have partially positive and partially negative charges, surround the DNA molecules and stabilize the negatively charged phosphate groups. Therefore, individual DNA molecules repel each other due to the presence of negative charges.

What Happens to DNA When Placed into an Aqueous Solution