Here are the vocabulary terms matched with their correct definitions:
1. **Substitution** - A mutation in which one base is replaced by another.
2. **Insertion** - A mutation involving the addition of one or more nucleotide base pairs into a DNA sequence.
3. **Nondisjunction** - The failure of homologous chromosomes or sister chromatids to separate during cell division.
4. **Deletion** - A type of mutation where a portion of the DNA is lost or removed.
5. **Allele** - A variant form of a gene that can appear in different forms.
6. **Codon** - A sequence of three nucleotides in mRNA that specifies an amino acid.
7. **Mutation** - A change in the DNA sequence that can lead to variations in organisms.
You can rearrange and input these matches as needed based on your application's format.