Below is a section of the human DHFR gene drawn seven times in the abbreviated “charm bracelet” format. “S” represents a sugar, “P” the phosphate group and G, A, T, C, and U represent the various nitrogenous bases found in nucleic acids. Only one structure is correct. Circle the correct structure. For all the rest, explain what is wrong with the drawing. There may be more than one error in each drawing and you should explain them all. When applicable, use terminology we used in class in your explanation.