In a diploid organism,crossing over is responsible for what?

The percentage of recombination between genes $A$ and $B$ is $9\%$,between $A$ and $C$ is $17\%$,and between $B$ and $C$ is $26\%$. What is the correct arrangement of these genes on the chromosome?

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

Discuss why Drosophila has been used extensively for genetical studies.

In maize, colored endosperm $(C)$ is dominant over colorless $(c)$ and full endosperm $(R)$ is dominant over shrunken $(r)$. When a test cross is performed on the $F_1$ generation, the following results are obtained:
Colored and Full = $45\%$
Colored and Shrunken = $5\%$
Colorless and Full = $4\%$
Colorless and Shrunken = $46\%$
Based on this data, what is the distance between the two non-allelic genes (in $units$)?

As the length of the chromosome increases in an organism,which of the following increases?