In genetics, regrouping of the maternal and paternal genes during the formation of sex cells (gametes). Recombination occurs randomly in nature as a normal event of meiosis. It is enhanced by crossing-over (seelinkage group). Recombination acts to ensure that no two daughter cells are identical, nor are any identical in genetic content to the parent cell. Laboratory study of recombination has contributed significantly to the understanding of genetic mechanisms, allowing scientists to map chromosomes, identify linkage groups, isolate the causes of certain genetic mistakes, and manipulate recombination itself by transplanting genes from one chromosome to another. See alsogenetic engineering, molecular biology.