Question

question 20 of 30 > which lettered box in the figure encloses a part of the molecule that is not part of the backbone of the dna strand?

Explanation:

The backbone of a DNA strand is composed of alternating sugar (deoxyribose) and phosphate groups. The nitrogen - containing base is not part of the backbone. Box W encloses a nitrogen - containing base (a pyrimidine derivative). Boxes X and Y enclose parts of the sugar - phosphate backbone (sugar and phosphate respectively).

Answer:

W.