Which of the following represent homologous features?
a. wings in birds and insects
b. the appendix in humans and horses
c. fins in fish and wings in birds
d. the striped coat of the zebra and the tiger

Part a - which gene to compare? in this exercise, you will use the cytochrome c oxidase i (coi) gene to investigate relationships among salmon species. (this gene encodes a protein that functions in the mitochondrial electron transport chain.) you will compare the coi gene sequences from your salmon test samples to the standard sequences for each salmon species. in order for the coi gene to be useful for distinguishing among the different salmon species, which three statements must be true?