In poultry, the comb is of four types that is rose comb controlled by dominant gene R, pea comb controlled by a dominant gene P. Single comb when both are recessive whereas walnut comb when both are dominant. Find out the phenotypic ratio in F2 generation when pure breeding rose comb fowl is crossed with pure breeding pea comb cock.

A pure tall plant bearing red colour flowers was crossed with a pure dwarf plant with white flowers,
(i) What would be the nature of offspring in the F1 generation?
(ii) If the offspring of the F1 generation are self-pollinated, what would be the ratio of red flowers to white flowers in the F2 generation?
(iii) What can you infer from the ratio obtained? Which law does it illustrate?

Define the following: Alleles.

Define the following : Law of dominance.