Who put forward the "Theory of linkage"?

Genetic recombination occurs through

In a certain plant, red flowers $(R)$ are dominant to white flowers $(r)$ and tallness $(T)$ is dominant to dwarfness $(t)$. $A$ heterozygous plant $(RrTt)$ is backcrossed with a double recessive plant $(rrtt)$. If the gene loci for colour and size are situated very close together on the same chromosome, the expected percentage of offspring could be approximately:

Tall Red

Tall White

Dwarf Red

Dwarf White

respectively.

In which of the following is the phenomenon of crossing over $NOT$ observed?

Mendel was successful in discovering the principles of inheritance because:

Which scientists proposed the coupling and repulsion theory?