The term normally applied when two genes fail to assort independently is

Linkage

This is the tendecy of the DNA that are close together and can be inherited together. The closer the two genes are to each other on the chromosome the greater the chance of being inherited together or linked. In contrast, genes that are far from each other on the same chromosome are likely to be separated during recombination. This is the process that occurs during Meiosis. The strength and chances of being inherited together depends on the distance between genes in same chromosome.