The example provided can help to clarify how a trait might be inherited but not always expressed. The F1 generation of pea plants was all tall because a tall pea plant and a dwarf pea plant were crossed. Selfed F1 plants generated plants that were both tall and dwarf in the F2 generation. This demonstrates that the F1 plants had inherited both of the parental traits but that they did not exhibit the recessive or dwarfing trait when the dominant trait was present.
This could be explained by the given cross :
