anticodons are found on

Brief Explanations

For the first question: tRNA (transfer RNA) has anticodons that pair with codons on mRNA during translation. mRNA has codons, rRNA is part of ribosomes, and DNA has genes (not anticodons in the context of translation).
For the second question: RNA has nitrogen - bases adenine, guanine, cytosine, and uracil. Thymine is a nitrogen - base in DNA, not in RNA.