Question

Watson and Crick built upon the work of many other scientists. Which of the following best describes Rosalind Franklin's contribution?

(A) The Diffraction Patterns indicate Phosphates must be on the outside of some helical structure.
(B) Nitrogenous bases must pair to their complement in DNA.
(C) The amount of A equals the amount of T, and the amount of C equals the amount of G.
(D) None of the above.

Answer 1

Rosalind Franklin's critical contribution to the discovery of the DNA structure was her X-ray diffraction evidence, which indicated a helical structure and guided Watson and Crick in constructing the double helix model.

Step-by-step explanation:

The best description of Rosalind Franklin's contribution is (A): The Diffraction Patterns indicate Phosphates must be on the outside of some helical structure. Franklin used X-ray diffraction methods to discover the helical nature of DNA, and her photographs provided James Watson and Francis Crick with crucial information that led them to formulate the double helix model of DNA, where phosphate groups are indeed on the outside.

Her X-ray diffraction images provided crucial information that allowed Watson and Crick to confirm that DNA forms a double helix and determine its size and structure. Franklin's work demonstrated the helical nature of DNA and was essential to the development of the double-stranded structural model of DNA by Watson and Crick.