GENETICS AND EVOLUTION
INHERITANCE AND VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Co-dominance
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Dihybrid cross
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Monohybrid cross with complete dominance
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Monohybrid cross with incomplete dominance
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Detailed explanation-1: -Final answer: F2 generation in a Mendelian cross with both genotypic and phenotypic ratios 1 : 2 : 1 is a case of incomplete dominance.
Detailed explanation-2: -The normal phenotypic ratio in F2 generation is 3:1 and the genotypic ratio is 1:2:1.
Detailed explanation-3: -Thus, the correct answer is ‘Incomplete dominance’.
Detailed explanation-4: -The F2 progeny of Mendel’s dihybrid cross exhibit four different phenotypes: round yellow, round green, wrinkled yellow and wrinkled green. There are 9 different genotypes: RRYY, RRYy, RrYY, RrYy-4 genotypes of the round yellow phenotype. RRyy, Rryy-2 genotypes of the round green phenotype.
Detailed explanation-5: -The F1 plants produce two types of gametes. Assuming that these gametes combine randomly, we could say that in the F2 generation, homozygous dominant, heterozygous dominant and homozygous recessive individuals are produced in a 1:2:1 ratio.