1) Term which indicates that an individual who is heterozygous at two neighbouring loci has the two mutations in question on the same chromosome.

3) characterised by having certain atoms or groups of atoms on the same side of the longitudinal axis of a double bond or of the plane of a ring in a molecule.

3) Relating to or being an arrangement of two very closely linked genes in the heterozygous condition in which both mutant alleles are on one chromosome and both wild-type alleles are on the homologous chromosome.