Which of the following statements correctly describes Chargaff's contribution to the study of DNA?
a. Chargaff hypothesized that DNA was a double helix, but he did not produce the image
that proved this fact.
b. Chargaff's experiments conclusively proved that DNA was made of nucleotides, but he
could not show that there four types of nitrogenous bases.
c. Chargaffs showed that adenine and thymine were found in equal percentages in DNA, but he did not know this was because of base-pairing.
d. Chargaff's work proved that DNA could be made using radioactive nucleotides, but he
did not show that DNA could be transferred from one organism to another.
Answer: c. Chargaffs showed that adenine and thymine were found in equal percentages in DNA, but he did not know this was because of base-pairing.