Lack of independent assortment of two genes A and B in fruit fly Drosophila is due to:
Lack of independent assortment of two genes A and B in fruit fly Drosophila is due to:
repulsion
recombination
linkage
crossing over.
Solution
Sex linkage was discovered by Thomas H. Morgan. He discovered it by conducting experiments on eye character in fruit fly, Drosophila. Independent assortment of genes does not occur during cell division.
Related Theory
Coupling and repulsion are two aspects of gene linkages. Coupling is the presence of two dominant alleles of two genes on the same chromosome $(A B)$. The remaining recessive genes of the two genes are present on the other chromosome (ab). Hence, the dominant alleles of genes tend to remain together. Repulsion is the presence of dominant genes on the two homologous chromosomes (Ab/aB).