GENETICS AND EVOLUTION
GENETIC BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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offspring will be Rr
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offspring will be RR
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round seeds will be recessive to wrinkled
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Wrinkled will be observed in half of offspring
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Detailed explanation-1: -A cross between homozygous round seeds plant (RR) and homozygous wrinkled seeds plant (rr) will produce heterozygous (Rr) round seeds plants as F1 generation.
Detailed explanation-2: -This means that plants with both genotypes WW and Ww have wrinkled seeds, and only those with genotype ww have round seeds. If two plants of genotype Ww are crossed, the probability an offspring has wrinkled seeds is 3/4, and the probability it has round seeds is 1/4.
Detailed explanation-3: -Based on this observation round seeds is the dominant phenotype. With dominant being round seeds that would mean wrinkle seeds are the recessive trait. Therefore a cross of heterozygous for round with a homozygous recessive for wrinkled, will yield an F1 generation that has 50% round seeds and 50% wrinkle seeds.
Detailed explanation-4: -In a homozygous plant round seeds (R) are dominant over wrinkled seeds (r). (i)Draw a Punnett square to show the gametes and offspring when both the plants have heterozygous round seeds (Rr). (ii) Mention the phenotype and genotype ratios of the offsprings in F2 generation.