-Genes situated on the same chromosome are said to be linked
-All genes on a single chromosome form a linkage group and usually pass into the same gamete and are inherited together e.g. sex linkage
-Genes belonging to the same linkage group usually do not show independent assortment
-i.e. do not conform to mendel’s principle of independent assortment (9:3:3:1)
-a variety of ratios are produced
two or more genes are said to be linked when phenotypes with gene combinations occur less frequently than the parental phenotypes