Polytene chromosomes in salivary glands of are formed as a result of

One of the parents of a cross has mutation in its mitochondria. In that cross, that parent is taken as a male. During segregation of $F_{2}$-progenies that mutation is found in

Expected children of a blue-eyed $(recessive)$ woman and brown-eyed $(dominant)$ man who had a blue-eyed mother are likely to be

Coupling and repulsion are the two faces of

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