Which sentence contains a capitalization error? A. My aunts and uncles are a lot of fun when they visit. B. The Middle School is conveniently located in the center of town. C. Studying engineering is a worthwhile pursuit. D. The American Medical Association, or AMA, is well respected.

Okay, biology isn't exactly my strongest subject (it never has been), but i'm pretty sure the answer is nucleotides. dna is made up of nucleotides. each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. there are four different nitrogen bases: adenine (a), thymine (t), guanine (g), and cytosine (c). a always pairs with t, and g always pairs with c.