Why does lemon brown smile at the end

Greg smiles at the end of “The Treasure of Lemon Brown” because his treasure is the love of his father expressed in the form of lectures telling him to work to be better. His treasure is stability and a home, even if he lets school work slide in favor of sports, just as Lemon Brown’s music and honor are his treasure. 

Honestly im just trying to get points i dont know the answer

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.