cross-over value

cross-over value

an estimation of the number of gametes that contain a gene combination produced by CROSSING OVER during MEIOSIS, as a proportion of all gene combinations in the gametes produced. The frequency produced by this calculation is used as a measure of GENETIC LINKAGE, one percent cross-over value being equivalent to one map unit.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005