Question

In a case of incomplete dominance, true breeding red flowered plant (RR) is crossed with true breeding white flowered plant (rr). What would be correct $F_2$ ratio?

• A. 1 red : 2 pink : 1 white
• B. 3 red : 1 white
• C. 1 red : 1 pink : 2 white
• D. 2 red : 1 pink : 1 white

Answer 1

The correct option is A 1 red : 2 pink : 1 white

Appearance of new phenotypes or intermediate phenotypes, other than parental phenotypes in progeny is incomplete dominance. A true breeding red fowered plant(RR) is crossed with true breeding white flowered plant(rr). In F1 generation, pink flowered plant(Rr) is formed. When this plant is subjected to self pollination, followed by fertilization, in the F2 generation, 1 red flowered plants(RR), two pink flowered plants(Rr), 1 white flowered plants(rr) are formed. So, the phenotypic and genotypic ratio is 1:2:1.

So, the correct option is ‘1 red:2pink:1 white’.