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.) Which of the following could explain the identical sequence in these otherwise differing genomes?
01. The sequence encodes a ribosomal protein that is critical for life and can not be easily mutated while retaining function.
02. The sequence is contained in a virus that has infected germline cells in both species.
03. The sequence is from an intron of a gene that encodes a muscle protein.
Provide a rationale for why each of the three statements above are correct or incorrect.
<span>Positive Homans'
medical Definition of Homans' sign. : pain in the calf of the leg upon dorsiflexion of the foot with the leg extended that is diagnostic of thrombosis in the deep veins of the area.</span>
