What is the number of linkage groups in humans with respect to $22$ pairs of autosomes?

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

The tendency of genes to remain together during the process of inheritance is known as

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?

What is the name of the pea species used by Bateson and Punnett in their experiments?

Discuss why Drosophila has been used extensively for genetical studies.