Which of the following fact was not established by the X-ray diffraction crystallography of purified DNA?

Correct option is B

Correct Answer: (b)
Explanation:
Equality of A = T and G = C is Chargaff’s rule, not discovered from X-ray diffraction studies. X-ray diffraction helped determine the helical shape and physical dimensions of DNA.
Information Booster:
Rosalind Franklin’s Photo 51 revealed helical structure.
The helix has a 3.4 nm length per turn.
Approximately 10 base pairs per helical turn.
Diameter of DNA is 2 nm.
Chargaff’s ratio was concluded from biochemical base composition studies, not from X-ray studies.
Additional Information (Incorrect Options):
(a), (c), (d) were indeed discovered from X-ray diffraction data.