There are three genes $a, b, c$ with 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 the chromosome?

In maize,the chromosome number is $2n = 20$. The number of linkage groups in it shall be:

Which of the following is true about linkage?
$I.$ It is a phenomenon in which more recombinants are produced in $F_{2}$-generation.
$II.$ More parental combinations are produced in $F_{2}$-generation.
$III.$ Genotypes which are present in $F_{1}$ hybrid reappear in high frequency in $F_{2}$-generation.
$IV.$ It is a phenomenon in which two chromosomes are linked.

In a fruit fly,the $X$-chromosome linkage map has a total length of $66$ units,with the yellow body gene $(y)$ at one end and the bobbed hair gene $(b)$ at the other end. What will be the recombination frequency between these two genes $(y$ and $b)$?

Which characteristic does not support Mendel's Law of Independent Assortment?

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?