| A | B |
|---|
| virus | package of nucleic acid wrapped in a protein coat that must use a host cell's machinery to reproduce itself |
| bacteriophage | virus that infects bacteria; |
| deoxyribonucleic acid | molecule responsible for inheritance |
| nucleotide | building block (monomer) of nucleic acid polymers |
| nitrogenous base | single or double ring of carbon and nitrogen atoms with attached functional groups, found in nucleic acids |
| pyrimidine | single-ring nitrogenous base |
| purine | double-ring nitrogenous base |
| double helix | two strands of nucleotides wound about each other; structure of DNA |
| DNA replication | process of copying DNA molecules |
| DNA polymerase | enzyme that makes the covalent bonds between the nucleotides of new DNA strands |
| RNA | nucleic acid containing the sugar ribose |
| transcription | process by which a DNA template is used to produce a single-stranded RNA molecule |
| translation | process by which a sequence of nucleic acids in RNA is used to direct the production of a chain of specific amino acids |
| codon | in RNA, a three-base "word" that codes for one amino acid |
| mRNA | RNA molecule transcribed from a DNA template |
| RNA polymerase | transcription enzyme that links RNA nucleotides together |
| intron | internal noncoding region in RNA transcript |
| exon | coding region in RNA transcript |
| RNA splicing | process by which the introns are removed from RNA transcripts and the remaining exons are joined together |
| tRNA | RNA that translates the three-letter codons of mRNA to amino acids |
| anticodon | in tRNA, a triplet of nitrogenous bases that is complementary to a specific codon in mRNA |
| rRNA | RNA component of ribosomes |
| mutation | any change in the nucleotide sequence of DNA |
| mutagen | physical or chemical agent that causes mutations |
