In a dihybrid cross,the $F_2$ generation ratio of $15:1$ is the result of:

Extranuclear inheritance is the result of the presence of genes in ........

The colour of the endosperm in maize is an example of:

Fruit colour in squash is an example of

When two non-allelic genes produce a new phenotype when present together, but fail to do so independently, what is this phenomenon called?

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