Why was protein originally thought to be the genetic information storage molecule instead of dna?

Prior to the development of dna fingerprinting, blood type could be used to determine possible parentage. although it might prove someone was not a parent, it could not show if someone was positively the parent, only that he or she might be a parent. which of the following is a true statement that can be made about parentage based on blood typing?

Tides that occur during the new and full moons

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?