primary consumers are herbivores, feeding on plants. secondary consumers, on the other hand, are carnivores, and prey on other animals. omnivores, who feed on both plants and animals, can also be considered a secondary consumer.
adenine, abbreviated 'a,' has a 2-ring structure, so that makes it a purine.
thymine, abbreviated 't,' is a pyrimidine, which means it has a 1-ring structure.
uracil, abbreviated 'u,' is found in rna.
guanine, abbreviated 'g,' is part of both dna and rna, where it bonds with cytosine.
they wee bond by there mates adenine is bond to thymine while cytosine is bond to guanine