In the 1940s, proteins were thought to be the more likely molecules to house genetic information. What was the primary reason that DNA was not originally believed to be the genetic material?
(a) DNA has a high density of negative charges.
(b) Nucleotides were known to be a source of chemical energy for the cell.
(c) Both protein and nucleic acids were found to be components of chromosomes.
(d) DNA was found to contain only four different chemical building blocks.
Answer: D