GENETICS AND EVOLUTION
INHERITANCE AND VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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This experiment does not follow the Principle of Dominance.
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Pink colour in F1 is due to incomplete dominance.
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Ratio of F2 is 1/4 (Red):2/4 (Pink):1/4 (White)
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Law of Segregation does not apply in this experiment
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Detailed explanation-1: -But after F1 was crossed, three kinds of combinations were obtained in F2 which were rr (white), RR (red) and Rr (pink). Hence, Antirrhinum (Snapdragon) follows the law of segragation but not the law of dominance. Q.
Detailed explanation-2: -Incomplete dominance The F1-hybrid plants have a different phenotype (pink flowers) than either of the true-breeding parents. This is an example of incomplete dominance.
Detailed explanation-3: -Complete answer: The color of the flower is controlled by a combination of two alleles. When a cross is made between two purebreds i.e dominant red flower-bearing plant with recessive white-bearing plant, all the progeny are hybrids i.e they all bear pink-colored flowers.
Detailed explanation-4: -For example, when red snapdragons (RR) are crossed with white snapdragons (WW), the F1 hybrids are all pink heterozygotes for flower color (RW). The pink color is an intermediate between the two parent colors. When two F1 (RW) hybrids are crossed they will produce red, pink, and white flowers.
Detailed explanation-5: -The genotype for the pink flower is Rr and the genotype for the white flower is rr. This would lead to a 50% chance of the offspring having a phenotype of pink.