An animal leaves its footprint in wet mud, and later, when the mud dries, the footprint can be filled with plaster. When the plaster hardens, it has same shape as the foot of the animal. The plaster cast could then be used to make new footprints in soft mud identical to those made by the animal. The
process of using the plaster cast to make new footprints most accurately models

translation of mRNA codons to form a protein.
transcription of mRNA from the original DNA code.

insertion of nucleotides into the mRNA codons

deletion of nucleotides from the tRNA anticodons.

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein