The scientists who proposed the theory of linkage are

What is the arrangement of genes on chromosomes resulting from crossing over called?

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

What map unit (Centimorgan) is adopted in the construction of genetic maps?

Two genes '$a$' and '$b$' show $20\%$ recombination. What will be the proportion of gametes produced by a dihybrid $F_1$ individual with the genotype $++/ab$,derived from a cross between $++/++$ and $ab/ab$?

Crossing over is