Question

Watson and Crick built upon the work of many other scientists. Which of the following best describes Chargaff's Rules?

(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

Chargaff's Rules describe that in DNA, the amount of adenine (A) equals that of thymine (T), and the amount of guanine (G) equals cytosine (C), which informed the complementary base pairing in the double helix structure proposed by Watson and Crick.

Step-by-step explanation:

The correct answer to the question "Which of the following best describes Chargaff's Rules?" is (C) The amount of A equals the amount of T, and the amount of C equals the amount of G. Erwin Chargaff's rules state that in DNA, the concentration of the nitrogenous bases adenine (A) always equals that of thymine (T), and the concentration of guanine (G) is always the same as that of cytosine (C). This discovery was crucial for James Watson and Francis Crick to propose their model of the DNA double helix, where A pairs with T, and G pairs with C, stabilized by hydrogen bonds in a specific pattern known as complementary base pairing. This rule has been consistently observed in all species, emphasising the universality of base pairing in the DNA structure.