GENETICS AND EVOLUTION
INHERITANCE AND VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a recessive allele
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a dominant allele
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a genotype
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a phenotype
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Detailed explanation-1: -A dominant allele is denoted by a capital letter (A versus a). Since each parent provides one allele, the possible combinations are: AA, Aa, and aa. Offspring whose genotype is either AA or Aa will have the dominant trait expressed phenotypically, while aa individuals express the recessive trait.
Detailed explanation-2: -Dominant alleles are seen as an uppercase of a letter; for example, B. Recessive alleles are seen as a lower case of a letter; b. In order for a person to show the dominant trait, one of the person’s parents must have the dominant trait (which is an uppercase letter).
Detailed explanation-3: -Codominance in humans is exemplified by individuals with type AB blood. A person inheriting the alleles IA and IB will have a type AB blood because IA and IB are codominant and therefore will be expressed together.
Detailed explanation-4: -Recessive alleles are denoted by a lowercase letter (a versus A). Only individuals with an aa genotype will express a recessive trait; therefore, offspring must receive one recessive allele from each parent to exhibit a recessive trait.