What is incomplete doniinance? Explain inheritance f flower colour in snapdragon.

Explanation

It is a process where the dominant gene is incompletely dominant over the recessive gene and produces a phenotype which is intermediate to the parental type. In Mirabilis or 4° clock plant, incomplete dominance has been reported with respect to colour of the flower. In these plants some produce red flowers and some others produce white flowers. When a plant producing red
flowers is crossed with a plant producing white flowers, in the `F_1` generation all plants produced pink flowers. It is a heterozygous condition and the pink character is an intermediate or a blend between red and white. This colour is produced because the red is being only partially dominant over white
`P_1 ` Red flowers `xx` white flowers
`F_1 ` pink flower
When `F_1` pink flower plants are self crossed to raise `F_2` progeny 3 types of plants are produced i.e, Red, Pink and White, in the ratio of 1:2:1 respectively.
By using appropriate symbols, the incomplete dominance can be represented as shown below. This cross is illustrated as indicated below by using appropriate letters.

Thus in this case, parental characters are expressed in homozygous conditions, and intermediate character in heterozygous condition.