EMBRYOLOGY
NERVOUS SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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True
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False
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Either A or B
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None of the above
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Detailed explanation-1: -So the dominant allele is always expressed, but it can differ in penetrance and is therefore not always as clearly expressed in the cell’s phenotype as you expect from a dominant allele.
Detailed explanation-2: -A dominant allele is an allele that is always expressed in the phenotype if present in the genotype. A dominant allele “dominates” over the recessive allele. In our example, the allele coding for blood group A is the dominant allele.
Detailed explanation-3: -Dominant phenotypes are always expressed if a dominant allele is present in the genotype. Thus, if the genotype is “AA” or “Aa", the dominant phenotype is expressed. In the second case, “Aa", both alleles are present, but the dominant allele dominates over the recessive allele.