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

Explanation

Mendel conducted a monohybrid cross / (crossed pure tall pea plants with pure dwarf pea plants) observed only tall pea plants in the `F_(1)` generation, but on selfing the `F_(1)` progeny both tall and dwarf pea plants were observed in `F_(2)` generation in the ration 3: 1. Appearance of tall character in `F_(1)` and `F_(2)` generations shows tallness to be a dominant character. But absence of dwarf character in `F_(2)` and its reappearance in `F_(2)` confirms that dwarfness is a recessive character.
(b) Mendel conducted a dihybrid cross and observed that though he started with two types of parents, he obtained four types of individuals in `F_(2)`. The appearance of new recombination in `F_(2)` generations along with parental type characters show that traits are inherited independently of each other.