Epistasis and dominance are respectively

In a cross between white-flowered parents,$F_1$ progeny was uniformly purple-flowered. The $F_2$ progeny showed a phenotypic ratio $9:7$ between purple-flowered and white-flowered plants. The above result indicates that the flower colour is controlled by

The progenies are found to be male sterile after crossing two plants. This is due to some genes,which are present in

$A$ farmer crossed a walnut-combed chicken with a single-combed one and obtained all walnut-combed chickens in $F_1$. The genotype of the parents was

In $Lathyrus$ $odoratus$,dominant genes $C$ and $P$ are required for the production of purple flower color. What will be the ratio of white to purple flowers in a cross between $CcPp$ and $Ccpp$?

$A$ gene that suppresses the expression of another non-allelic gene,where the suppressed gene is not located on the same homologous chromosome pair,is known as what?