| A | B |
| Monohybrid | A cross involving just one gene eg Aa x Aa |
| Dominant | In a heterozygote (Bb) only the dominant allele is expressed (B in this case) |
| Recessive | In a heterozygote (Bb) the recessive allele is not expressed (b in this case) |
| Heterozygote | Has a recessive and a dominant allele (Bb) |
| Homozygote | Both alleles are recessive (bb) or both are dominant (BB) |
| Allele | The form of a gene |
| Children | The F1 generation |
| Grandchildren | The F2 generation |
| Mendel | Austrian monk who discovered how genetic crosses work |
| Genotype | The name for a description of which alleles you have |
| Phenotype | The name for a description of what you look like |
| Test cross | A cross with a homozygous recessive (bb) to find out if an organism is BB or Bb |
| Family tree | Used in a pedigree analysis to work out if a condition has been inherited |
| Gene | A length of DNA which codes for a protein |
| Sweet peas | Mendel did most of his work on genetic crosses using these plants |
| Mutation | The reason you might have different alleles than either of your biological parents |
| Statistically perfect | The reason some scientists think that Mendel faked some of his results (using educated guesses - rather than counting plant types) |
| Chromosomes | Made up of a lot of genes joined together |
| Protein | The type of molecule which is coded for by a gene |
| Iris | The part of the eye which gives you your 'eye colour' |