I believe it is D. More African elephants today naturally lack tusks compared to the elephant populations 100 years ago, because big game hunters sought elephants for ivory.
Because the nucleotides match up like A and T and C and G is is like a zipper there is two parts that go together
DNA, which is a sequence of nucleotides, make up genes. Genes are DNA sequences that code of a functional protein and are controlled by a promoter region on the DNA. DNA, including genes within it, are supercoiled into chromosomes so they are able to fit in the cell. Otherwise, uncoiled DNA in a cell is much longer than the cell itself.
