The first mutant gene reported by $T.H. Morgan$ in $Drosophila$ was the . . . . . . .

When linked characters or genes are inherited together through two or more generations,it is called

There are three genes $a, b,$ and $c$. The percentage of crossing over between $a$ and $b$ is $20\%$,between $b$ and $c$ is $28\%$,and between $a$ and $c$ is $8\%$. What is the sequence of these genes on the chromosome?

Select the correct statement regarding the dihybrid cross experiment.

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?

Which of the following is suitable for the study of linkage?