A base is part of a nucleotide so that eliminates choice D. Pyrimidine and Cytosine only have 1 base, Purine is the only one with two, therefore Purine is the answer.
Which of the following is a good definition for the word adaptation? question 1 options: a trait that an organism survive and reproduce in its environment. a change in an organism's environment. the way in which animals obtain food. a temperature change that can cause the extinction of plants and animals.