Can you be more specific with the question. Are you talking about DNA coding with complementary bases?
Transfer<span> ribonucleic acid (tRNA) is a type of </span>RNA<span> molecule that helps decode a </span>messenger RNA<span> (mRNA) sequence into a protein. tRNAs</span>function at specific sites in the ribosome during translation, which is a process that synthesizes a protein from an mRNA molecule. or check this site out it might help http://www.nature.com/scitable/definition/trna-transfer-rna-256
C) Satellites
Since they view from a distance and aren’t Immersed in the environment they are witnessing