How do Mendel’s experiments show that the (a) traits may be dominant or recessive, (b) traits are inherited independently?

(a) While doing experiments with pea plants when Mendel crossed pollinated pure tall pea
plants with pure dwarf pea plants, only tall plants were obtained in F1 generation. On self-pollinating the F1 progeny, both tall and dwarf plants appeared in F2 generation in the
ratio 3 : 1.
Appearance of tall character in both the F1 and F2 shows that tallness is the dominant character. The absence of dwarf character in F, generation and its reappearance in F2 generation shows dwarfness is the recessive character.
(b) When Mendel conducted a dihybrid cross with pea plants having two sets of characters, he obtained only one set of parental characters in F1 generation, whereas in F2 generation he obtained both the set of parental characters now recombined in the ratio of
9 :3 :3:1.
The appearance of new recombinants in the F2 generation along with parental type shows that traits are inherited independently.