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Imagine a genomic researcher who is analyzing the genome of different types of c

ID: 301121 • Letter: I

Question

Imagine a genomic researcher who is analyzing the genome of different types of cats. She finds that a particular sequence in the North American Bobcat genome is exactly homologous to a sequence found in the common house cat, while all other sequences in those two genomes differ at many nucleotides. (The most recent common ancestor between bobcats and house cats is estimated to be about 6.8 million years, plenty of time for mutation to generate DNA sequence variation.)

31. Imagine a genomic researcher who is analyzing the genome of different types of cats. She finds that a particular sequence in the North American Bobcat genome is exactly identical to a sequence found in the common house cat, while most other sequences in those two genomes differ at many nucleotides. (The most recent common ancestor between bobcats and house cats is estimated to be about 6.8 million years, plenty of time for mutation to generate DNA sequence variation.) Which of the following could explain the identical sequence in these otherwise differing genomes? (Select all that apply.) The sequence encodes a protein critical for the production of fur color. The sequence encodes a gene that is critical for life and cannot be easily mutated while retaining function. The sequence is contained in a retrovirus that has infected both species. The sequence is from an intron of a gene that encodes a muscle protein.

Explanation / Answer

The identical sequence could be of

1. The sequence encodes a protein critical for the production of fur colour

2. The sequence encodes a gene that is critical for life and can not be easily mutated while retaining function

3. The sequence is from an intron of a gene that encodes a muscle protein

The sequences that are retained without mutation are called conserved sequences. These conserved sequences can be seen in distantly related members.