Linkage decreases the frequency of

The experiment shown in the given figure has been carried out by Morgan to show the phenomenon of linkage and recombination. If in cross $I$, genes are tightly linked and in cross $II$, genes are loosely linked then what will be the percentage of recombinants produced in cross $I$ and cross $II$ respectively?

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 and situated very close together on the same chromosome, the expected percentage of offsprings could be approximately

 respectively

In Drosophila, long wing and broad abdomen characters are dominant over to characters vestigeal wing and narrow abdomen. A pure breeding Drosophila having long wings and broad abdomen is crossed with a pure breeding vestigeal-winged and narrow-abdomened Drosophila. Two of the $F_1$ individuals were crossed and the following results were produced in the $F_2$ generation Long wing, broad abdomen in $482$ Drosophila. Vestigeal wing, narrow abdomen in $154$ Drosophila. Which one of the following is illustrated by these results

There are three genes $a,\,b,\,c$. 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 chromosome ?