[Campbell Biology P.7] Based on the diagram "How can one change in DNA result in such a dr... | Practice Question

Based on the diagram "How can one change in DNA result in such a dramatic change in appearance?", which statement accurately describes the flow of genetic information and the consequence of the depicted mutation?

  • A: The mutation in the gene for pigmentation directly alters the mRNA, leading to a functional enzyme and brown pigment.
  • B: Gene expression involves transcription of DNA to mRNA, followed by translation of mRNA to protein, and a mutation can cause the resulting protein to be non-functional, leading to a different phenotype.
  • C: The diagram shows that the "no pigment" phenotype is due to the lack of transcription, while the "brown pigment" phenotype results from complete protein synthesis.
  • D: A mutation in the gene prevents the synthesis of mRNA, thus no protein is produced and no pigment appears.

Explanation

The diagram clearly illustrates the central dogma: DNA undergoes transcription to produce mRNA, which then undergoes translation to produce a protein. In the case of the mutation, the 'Gene for pigmentation with mutation' still undergoes transcription to mRNA and translation to protein, but the resulting 'Protein: Enzyme required for pigment synthesis does not work', leading to the 'No pigment' phenotype. Option B accurately encapsulates this flow and the consequence of the mutation.