In a desert environment, cactus wrens often build their nests in cholla cacti to avoid predators. This behavior does not hurt the cacti. Which type of relationship do cactus wrens and cholla cacti demonstrate?
A B C D
competitive commensalism mutualism parasitism
Question: In a desert environment, cactus wrens often build their nests in cholla cacti to avoid predators. This behavior does not hurt the cacti. Which type of relationship do cactus wrens and cholla cacti demonstrate?
(A) competitive
(B) commensalism
(C) mutualism
(D) parasitism

Answer: (B) commensalism
Answer: (D) parasitism
Question: In a desert environment, cactus wrens often build their nests in cholla cacti to avoid predators. This behavior does not hurt the cacti. Which type of relationship do cactus wrens and cholla cacti demonstrate?
(A) competitive
(B) commensalism
(C) mutualism
(D) parasitism
Answer: (B) commensalism