Linkage with increasing age becomes ......

How many types of gametes will be produced by a male Drosophila having the following arrangement of two genes ($y$ and $w$) on the $X$-chromosome?

Genes on the same chromosome can be:

There are three genes $a, b,$ and $c$. The percentage of crossing over between $a$ and $b$ is $20\%$,between $b$ and $c$ is $28\%$,and between $a$ and $c$ is $8\%$. What is the sequence of these genes on the chromosome?

The coupling and repulsion theory was proposed by:

When two genes are situated very close to each other on a chromosome: