Question

Lack of independent assortment of two genes A and B in the same chromosome of Drosophila melanogaster is due to

• A. recombination
• B. linkage
• C. crossing over
• D. chiasmata formation

Answer 1

The correct option is B linkage

The Law of independent assortment states that at the time of gamete formation, different genes assort or separate independently into the gametes and get randomly arranged in the progeny producing both parental as well as new combinations of characters.

Linkage is the association or tendency of the genes on a chromosome to remain together and inherit in groups rather than assort independently.
Crossing over and recombinations are the phenomenon that breaks the linkage between the genes. In linkage, genes tend to remain stuck to each other and retain parental combinations while recombination is the sorting of alleles into new combinations other than the parental ones.