KCET 2020 Biology Solved Paper

In the population of plants, tall and dwarf are the extreme phenotypes and medium height is the intermediate phenotype.
When nature selects the extreme phenotypes, the population is said to be disruptive. Here most of the members with intermediate height will be eliminated.
If the intermediate phenotype is chosen then the population is said to be stabilising. The directional selection is also called balancing selection.
If either of the extreme phenotypes is selected by nature then the population is directional.
This means that in this type of selection, nature can favour tall or dwarf individuals and more individuals of that type will be present in the next generation.