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

In Mendelism, linkage was not observed due to

Give differences : Crossing over and Linkage
 

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

Percentage of recombination between $A$ and $B$ is $9\%$ and $C$ is $17\%$, $B$ and $C$ is $26\%$, then the arrangement of genes is