Two pink coloured flowers on crossing resulted in 1 red, 2 pinkand 1 white flower progeny. The nature of the cross will be

The nature of the cross described in the question is a classic example of incomplete dominance. Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely expressed over its paired allele. This results in a third phenotype in which the observed characteristics are a mixture of those of the two alleles.

Here's the step-by-step explanation:

1. The pink flowers are the result of incomplete dominance between red and white flowers. In this case, the red color (R) and the white color (W) are the two alleles, and the pink color is the result of their incomplete dominance (RW).

2. When two pink flowers (RW) are crossed, the possible combinations of alleles in the progeny are RR, RW, WR, and WW.

3. RR will result in a red flower, RW and WR will result in pink flowers, and WW will result in a white flower.

4. Therefore, the ratio of red:pink:white flowers is 1:2:1, which matches the result given in the question.