Explain the Law of Dominance using a monohybrid cross.

Mendel's law of dominance states that a dominant allele expresses itself in a monohybrid cross and suppresses the expression of recessive allele. However, this recessive allele for a character is not lost and remains hidden or masked in the progenies of $\mathrm{F}_{1}$ generation and reappears in the next generation.

For example, when pea plants with round seeds $(RR)$ are crossed with plants with wrinkled seeds $(rr)$, all seeds in $\mathrm{F}_{1}$, generation were found to be round $(Rr)$. When these round seeds were self-fertilized, both the round and wrinkled seeds appeared in $\mathrm{F}_{2}$ generation in $3: 1$ ratio. Hence, in $\mathrm{F}_{1}$ generation, the dominant character (round seeds) appeared and the recessive character (wrinkled seeds) got suppressed, which reappeared in $\mathrm{F}_{2}$ generation. (figure)