SAT Subject Biology Practice Question 200: Answer and Explanation
10. Which of these are relationships in which one species benefits at the expense of another?
A. III only
B. III and IV
C. I, II, and III
D. II, III, and IV
E. I, II, III, and IV
Correct Answer: D
In competition, parasitism, and predation, one species benefits at the expense of the other. Commensalism is an ecological relationship in which one species benefits while the other is neither helped nor harmed.