Answer:
landmarkes
Explanation:
i took a test abt it last year and i got it right
D. proteins is the right answer
Two alleles hope it helped
A dna double helix consists of a purine base, such as adenine and guanine, paired with its complementary pyrimadine base, such as thymine and cytosine.
Adenine pairs with thymine; A-T
Cytosine pairs with guanine; C-G