How did Mendel explain that it is possible that a trait is inherited but not expressed in an organism? (AI 2017)

Mendel started by selecting two pure-line plants. Then he crossed such plants with different characteristics. He observed that only one of the two opposing characters—which he termed dominant—appeared in the F₁ generation and that the other was recessive. Later, when he selfed the F₁ plants, he observed that both features did indeed arise but in a certain proportion.

  It can be explained by the following cross :

This is how Mendel explained that a trait may be inherited but not expressed in the plant.

F2 generation result

Phenotype

Tall = 3

Dwarf = 1

Phenotypic ratio = 3:1

Genotype

Pure tall (TT) = 1

Hybrid tall (Tt) = 2

Pure dwarf (tt) = 1

Genotypic ratio = 1:2:1