Sex linkage was first observed by.....

Mendel observed that some characters did not assort independently. Later researchers found it to be due to

Continuous variations are attributed to

Crossing over in a diploid organism is responsible for

In $Drosophila$,crossing over occurs in females but not in males. Genes $A$ and $B$ are located on a chromosome at a distance of $10 \ cM$. The genotype of the female $Drosophila$ is $AB/ab$ and the genotype of the male $Drosophila$ is $AB/ab$. How many types of gametes are produced by the female and male $Drosophila$,respectively?

The arrangement of genes on chromosomes is