Complete linkage is observed in.....

In female $Drosophila$,linked genes show recombination during meiosis. However,such recombination does not occur during sperm formation in male $Drosophila$. Why?

Genes $p, q,$ and $r$ are arranged on a chromosome. If the recombination frequency between $p$ and $q$ is $10 \%$,the recombination frequency between $q$ and $r$ is $20 \%$,and the recombination frequency between $p$ and $r$ is $10 \%$,what is the order of the genes on the chromosome?

Choose the incorrect statement.

Incomplete linkage is $A$. Complete linkage is $B$. Choose the correct option for $A$ and $B$.

What is a linkage group?