SAT Subject Biology Practice Question 105: Answer and Explanation
15. An association between two organisms in which one benefits and neither is harmed is called
Correct Answer: A
Commensalism is a relationship between organisms that has no negative effects on one party but has great benefit for another. An example is moss that grows on trees: the moss obtains a nutrient-rich habitat and can access sunlight, while the tree's function is unaffected by the presence of the moss.