LAW OF DOMINANCE USING A MONOHYBRID CROSS
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The Law of dominance is given by Mendel, which is stated as below: "In a cross of parental generations that are pure for contrasting traits, only one form of the trait will appear in the next generation. Offspring that are hybrid for a trait will have only the dominant trait in the phenotype."
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With reference to monohybrid cross it means that a dominant allele expresses itself in a monohybrid cross and suppresses the expression of recessive allele.
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However, the recessive allele is not lost but it is masked by the dominant allele in F1 generation and gets reappeared in next generation.
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For example, when pea plants with round seeds (RR) are crossed with plants with wrinkled seeds (rr), all seeds in F1 generation were found to be round (Rr).
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When these F1 generation is self fertilized both the round and wrinkled seeds appeared in F2 generation in 3:1 ratio.
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This means that the suppressed gene (r) of wrinkled seeds were not omitted from F1 generation, they are just masked by dominant gene (R) of round seeds.
