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Which of the following statements about dominance is accurate?

A) Dominant alleles silence recessive alleles by preventing their transcription
B) Loss of function alleles are often recessive because one functional copy of haplosufficient genes is enough to support a wild type phenotype
C) The nucleotide sequence of recessive alleles is different than wild type, so they are no longer the same gene
D) Dominance describes a genetic relationship where the phenotype of one gene masks the phenotype of another gene
E) both C and D are accurate

User Jaromir
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Final answer:

The accurate statement about dominance is that loss of function alleles are often recessive because a single functional allele is sufficient for a normal phenotype. Dominant alleles do not silence recessive alleles through preventing their transcription; they simply express the dominant trait. The concept that dominance is a gene-gene interaction is actually epistasis, not dominance.

Step-by-step explanation:

The correct statement about dominance is: B) Loss of function alleles are often recessive because one functional copy of haplo sufficient genes is enough to support a wild type phenotype. This is often observed when the recessive allele is defective and the single normal allele produces enough of the gene's product to manifest the dominant phenotype. Dominant alleles do not silence recessive alleles by preventing their transcription; rather, the phenotype associated with the recessive allele is not observed because the dominant allele's function compensates for it.

Dominance, indeed, does describe a relationship where one allele can mask the expression of another. However, dominance doesn't necessarily represent a gene-gene interaction as described in option D. That is more accurately termed epistasis.

The nucleotide sequence of a recessive allele may differ from the wild type, but it is incorrect to say they are no longer the same gene as stated in option C. They are still variants of the same gene.

User Himanshu Yadav
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