ˌcomplemenˈtation

/ ˌkɒmplɪmɛnˈteɪʃən /

noun

1. the act or process of forming a complement
2. genetics the combination of two homologous chromosomes, each with a different recessive mutant gene, in a single cell to produce a normal phenotype. The deficiency of one homologue is supplied by the normal allele of the other