Question

An individual has a mutation in the gene that codes for hemoglobin. This results in sickle cell disease. Choose the correct explanation for how this mutation affects the individual's traits.
a. The error in the DNA sequence results in an error in the mRNA molecule during transcription, the error in the mRNA molecule results in an incorrect amino acid in the hemoglobin protein which makes it non-functional. The resulting trait is sickle cell disease.
b. The error in the mRNA sequence results in an error in the DNA molecule during transcription, the error in the DNA molecule results in an incorrect nucleic acid in the hemoglobin protein which makes it non-functional. The resulting trait is sickle cell disease.
c. The error in the DNA sequence results in an error in the mRNA molecule during transcription, the error in the mRNA molecule results in an incorrect nucleic acid in the hemoglobin protein which makes it non-functional. The resulting trait is sickle cell disease.
d. The error in the mRNA sequence results in an error in the DNA molecule during transcription, the error in the DNA molecule results in an incorrect amino acid in the hemoglobin protein which makes it non-functional. The resulting trait is sickle cell disease.

Answer 1

Answer:

a

Explanation:

The correct answer would be that the error in the DNA sequence results in an error in the mRNA molecule during transcription, the error in the mRNA molecule results in an incorrect amino acid in the hemoglobin protein which makes it non-functional. The resulting trait is sickle cell disease.

The direction of the flow of information during genetic inheritance is from DNA to mRNA and finally to protein. The information in the DNA is encoded into mRNA during transcription and the encoded information is translated into protein during the process of translation.

Hence, once there is an error in the DNA, the error is passed on to the mRNA during transcription. The consequence of this error is that the wrong amino acid is translated from the wrong codon.

Hence, the substitution of the correct amino acid by the wrong one in the hemoglobin protein results in a defect or non-functional protein. One of the phenotypic implications of this kind of error is sickle cell disease.

The correct option is a.