The DNA sequence of a conserved region of the mouse Pax6 gene is from 77 to 85 percent identical to that of homologs from distant animal relatives. Yet the amino acid sequence identity among the homologs is 100 percent. How can this be?
A) The genetic code is degenerate.
B) There were errors in transcription.
C) There was a frame-shift mutation.
D) Codon usage varies.
E) Both a and d

Question

Quizplus · Accepted Answer

The genetic code is degenerate, meaning that multiple codons can code for the same amino acid. This allows for some variation in the DNA sequence without changing the amino acid sequence. Additionally, codon usage can vary between species, which can also contribute to the difference in DNA sequence identity while maintaining 100% amino acid sequence identity.

The DNA Sequence of a Conserved Region of the Mouse