| A | B | 
|---|
| Nitrogen Bases | For example, adenine, cytosine, guanine, thymine | 
| Double Helix | Watson and Crick found the structure of DNA to have this shape. | 
| Replication | When DNA makes an exact copy of itself. | 
| Gene | A portion of a DNA molecule that is the code for a single protein. | 
| Codon | A triplet on mRNA. | 
| Transcription | The process of making a mRNA. | 
| mRNA | Carries the code from DNA to the ribosome. | 
| tRNA | Brings amino acids to the ribosome. | 
| Anticodon | A triplet on a tRNA, bonds to the codon. | 
| Mutation | Any mistake or change in the DNA sequence. | 
| Point Mutation | A change in a single base pair of DNA. | 
| Frame Shift Mutation | A mutation in which a single base is added or deleted from DNA. | 
| Chromosomal Mutation | A mutation at the chromosome level. | 
| Nondisjunction | The failure of homologous chromosomes to separate properly during meiosis. | 
| Karyotype | A charted arrangement of chromosomes. | 
| Trisomy | When a zygote gets an extra chromosome. | 
| Monosomy | When a zygote is missing a chromosome. |