Q. In a certain plant red colour flower (R) is dominant over white colour flower (r). When heterozygous Rr plant is crossed 64 offsprings are obtained. The number of white offsprings are:

 1468  176 Delhi UMET/DPMTDelhi UMET/DPMT 2002 Report Error

Solution:

This may be an example of complete dominance or incomplete dominance (in both the case the white flowered ratio remains same). In complete dominance when Rr (heterozygous) are selfed then the red and white flower are obtained in 3 : 1 ratio whereas in incomplete dominance the ratio of red, pink and white is 1 : 2 : 1. i. e., the white flowers are same in number (16 here).