Final answer:
Gene sequences do not always correspond exactly to the respective protein sequences produced from them due to non-coding regions, degenerate genetic code, and post-translational modifications.
Step-by-step explanation:
The gene sequences do not always correspond exactly to the respective protein sequences produced from them. There are several reasons for this. First, genes contain non-coding regions, such as introns, which are removed during the process of transcription. Second, the genetic code is degenerate, meaning that multiple codons can code for the same amino acid. Lastly, post-translational modifications can alter the protein sequence after translation. These modifications can include the addition of chemical groups or the cleavage of certain segments of the protein.
For example, the protein sequence of cytochrome c from chimpanzees and humans is identical, but the protein sequence of cytochrome c from rhesus monkeys differs from the human sequence by one amino acid. This difference suggests that there has been a mutation in the gene sequence of cytochrome c in rhesus monkeys that has resulted in a change in the protein sequence.