| Term | Definition |
| transcription | copying the code from DNA onto mRNA |
| codon | three mRNA nucleotides that code for a specific amino acid |
| translation | process by which a ribosome uses the code on mRNA to make proteins |
| nucleotide | building block of a nucleic acid (DNA and RNA) |
| chromatin | DNA that is coiled around proteins |
| amino acid | building block of a protein |
| mRNA | messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome |
| polypeptide | synonym for protein; chain of amino acids |
| replication | process in which DNA is duplicated |
| rRNA | ribosomal RNA; type of RNA that makes up part of the ribosome |
| mutation | a change or error in the DNA sequence |
| tRNA | transfer RNA; type of RNA that carries amino acids to the ribosome |