Question

You are studying the amino acid sequence of a protein shared by four organisms. You want to know which organism is most closely related to organism A. You have data that shows the number of amino acid differences between organism A and each of the other organisms. Study the data in the chart and use it to answer the question.

Which organism does this data suggest is most closely related to organism A?
A. Organism A
B. Organism B
C. Organism C
D. Organism D

Answer 1

Question

I found the chart from another source and it contains the following information:

Number of differences in amino acid sequence from Organism A

• Organism B - 3
• Organism C - 5
• Organism D - 1

Answer:

D

Step-by-step explanation:

Closely related proteins will have DNA sequences more similar to one another than less related organisms. DNA sequences determine amino acid sequences, therefore any changes in DNA sequence is reflected in the amino acid sequence.

Organism D has the least changes in amino acid sequence in this protein compared to A, suggesting it is most closely related.