During his studies on genes in Drosophila that were sex-linked, TH Morgan found $F_{ 2 }$ -population phenotypic ratio to be deviated from expected 9: 3: 3:1. Explain the conclusion he arrived at.
Conclusion of Morgan’s experiments are:
(i) Genes were located on the X-chromosome.
(ii) When the two genes in a dihybrid cross were studied on the same chromosome, the proportion of parental gene combinations were much higher than the non-parental type.
Morgan stated this association as ‘linkage’ to describe the physical association of genes on a chromosome.
(iii) Morgan and his group also found that even when genes were grouped on the same chromosome, some genes were tightly linked (low recombination) and others were loosely linked (high recombination).