What will be the number of linkage groups in maize if it has $10$ pairs of chromosomes?

Genes $A$ and $B$ are linked. What will be the genotype of the offspring produced by a cross between $AB/ab$ and $ab/ab$?

In a fruit fly,the $X$-chromosome linkage map has a total length of $66$ units,with the yellow body gene $(y)$ at one end and the bobbed hair gene $(b)$ at the other end. What will be the recombination frequency between these two genes $(y$ and $b)$?

When a group of genes exhibits linkage,they:

Thomas Hunt Morgan and his colleagues performed experiments on which organism to verify the chromosomal theory of inheritance and later demonstrated linkage?

Who mapped the position of genes on chromosomes by using the frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes?