Question

what did chargaffs team find during their experiments with dna in different species?
a. purines always appeared in larger amounts than pyrimidines.
b. multicellular species contained mostly pyrimidines.
c. the ratio of purines to pyrimidines varied widely among species.
d. the amount of purines was always the same as the amount of pyrimidines.

Explanation:

Chargaff's rules state that in DNA, the amount of adenine (A) equals thymine (T) (both purines and pyrimidines respectively in a way that A - T pair), and the amount of guanine (G) equals cytosine (C) (another purine - pyrimidine pair). So, overall, the amount of purines (A + G) is equal to the amount of pyrimidines (T + C).

Answer:

D. The amount of purines was always the same as the amount of pyrimidines.