Crossing over in diploid organism is responsible for

For the preparation of genetic maps, the recombination frequencies between genes are additive over short distances but not over long distances due to

Given below are two statements : one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.

Assertion $(A)$:

Mendel's law of Independent assortment does not hold good for the genes that are located closely on the same chromosome.

Reason $(R):$

Closely located genes assort independently.

In the light of the above statements, choose the correct answer from the options given below:

The frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes was explained by

The term “linkage” was coined by

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