Genetic interference Positive interference: the interaction between crossovers such that the occurrence of one exchange between homologous chromosomes reduces the likelihood of another in its vicinity.

Negative interference: a situation in which the coefficient of coincidence is greater than 1. In such cases, the occurrence of one exchange between homologous chromosomes appears to increase the likelihood of another in its vicinity.

Chiasma interference: the more frequent (in the case of negative chiasma interference) or less frequent (in the case of positive interference) occurrence of more than one chiasma in a bivalent segment than expected by chance.

Centromere interference: the inhibitory effect of the centromere upon crossing over in adjacent chromosomal regions.