Question

based on the biochemical analysis of the organisms in the chart, which two would be more closely related?
species | sequence of amino acids in the same part of the hemoglobin molecules
human | lys-glu-his-iso
horse | asp-lys-his-lys
gorilla | lys-glu-his-lys
chimpanzee | lys-glu-his-iso
zebra | arg-lys-his-arg
options: human and gorilla, human and zebra, human and horse, human and chimpanzee

Explanation:

To determine relatedness, we compare amino acid sequences. Human: Lys - Glu - His - Ile; Chimpanzee: Lys - Glu - His - Ile (identical). Gorilla: Lys - Glu - His - Lys (differs at 4th). Horse: Asp - Lys - His - Lys (differs at 1st, 4th). Zebra: Arg - Lys - His - Arg (differs at 1st, 4th). Identical sequences mean closer relation. Human and chimpanzee have the same amino acid sequence for the hemoglobin part, so they are more closely related.

Answer:

Human and chimpanzee