Question

What is the law of dominance of traits? Explain with an example.

Answer 1

Law of dominance of traits: It states that “When parents having pure contrasting characters are crossed then only one character expresses itself in F₁ generation. This character is the dominant character and the character which cannot express itself is called recessive character”.

Let’s use the tall and dwarf pea plant as an example. All of the offspring produced by crossing pure line tall (TT) plants with pure line dwarf (tt) plants were heterozygous tall (Tt). Tallness is the dominant feature while dwarfism is a recessive trait as shown by the presence of every tall plant in the F₁ generation. In the F₂ generation, the tall to dwarf ratio is 3 : 1.