Question

You have identified a previously unknown human gene that appears to have a role in autism. It is similar enough in DNA sequence to a known mouse gene that you believe that the two genes may be evolutionarily related. You determine and compare the DNA sequences, the predicted mRNA sequences, and the predicted amino acid sequences corresponding to the two genes. You would expect to find the greatest sequence similarity from comparisons of the two:

a. DNA sequences (13.6%)
  b. mRNA sequences (3.9%)
  c. Amino acid sequences (51.5%)
  d. All three comparisons are likely to show the same degree of sequence similarity (31.0%)

Answer 1

The greatest sequence similarity between the identified human gene and the known mouse gene would be expected in the amino acid sequences (51.5%).

Step-by-step explanation:

Based on the information provided, the greatest sequence similarity between the identified human gene and the known mouse gene would be expected from comparisons of the amino acid sequences (51.5%). This is because the sequence of amino acids determines the structure and function of proteins, and similarities in the amino acid sequence usually indicate evolutionary relatedness. Comparisons of DNA sequences and mRNA sequences are also important but may show a lower degree of similarity due to variations in non-coding DNA regions and post-transcriptional modifications.

Answer 2

Amino acid sequences

Step-by-step explanation:

The proteins perform the vast majority of functions in the cells. If a gene between a human and a mouse is evolutionarily related, it means that the function they do in the cell is quite similar in both species. This is the reason why the amino acid sequence would be the most similar.

In addition, there might be certain mutations in the DNA and therefore in the RNA between this 2 sequences that encode to the same amino acid sequence. More specifically speaking, there are more than one codon that encode to the same aminoacid. Thus, 2 different DNA/RNA sequence can give the same aminoacid sequence.