Q.4. 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 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 generation were found to be round (Rr). When these round seeds were self-fertilized, both the round and wrinkled seeds appeared in generation in 3: 1 ratio. Hence, in generation, the dominant character (round seeds) appeared and the recessive character (wrinkled seeds) got suppressed, which reappeared in generation.