OBJECTIVE LIFE SCIENCE
GENETICS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The allele for purple flowered plants is recessive
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The allele for white flowered plants is dominant
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The allele for purple flowered plants is dominant
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They were homozygous like their parents
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Detailed explanation-1: -The answer is c) dominant. In a true-breeding plant, the genotype is homozygous so we can assume the purple-flowered plants had the genotype PP and the white-flowered plants had the genotype pp.
Detailed explanation-2: -Mendel crossed pure lines of pea plants. Dominant traits, like purple flower colour, appeared in the first-generation hybrids (F1), whereas recessive traits, like white flower colour, were masked. However, recessive traits reappeared in second-generation (F2) pea plants in a ratio of 3:1 (dominant to recessive).
Detailed explanation-3: -Mendel’s Laws of Heredity Mendel discovered that by crossing true-breeding white flower and true-breeding purple flower plants, the result was a hybrid offspring. He did this by cross-breeding dihybrids; that is, plants that were heterozygous for the alleles controlling two different traits.