30. The following are characteristics of invertebrates except one. A They have backbones. B. They have solt bodies. C. They are cold blooded animals. D. Some have a single cell membrane. 31. In a coral reef ecosystem, clown fishes and sea anemones live together. What type of relationship do they have? A Mutualism B. Commensalism C. Predation D. Parasitism 32. Which of the following does NOT the benefit of coral reefs? A serve as the breeding ground for marine animals B. protect the coastal areas from strong waves C. provide food sources for marine animals D. plastic weste stuck in the coral reefs 33. Which of the following is the producer in the coral reef ecosystem? A. sea algae B. mangrove C. corals D. big fishes 34. Which of the following is the abiotic factor in the mangrove swamp ecosystem? A. mangroves B. hermit crabs C pelicans D. mud 35. Why can mangrove plants survive in brackish water while the other plants cannot? A Mangroves have roots that can filter salt water and release them through their leaves. B. Mangroves have strong trunk and roots C. Mangroves can adapt in the salt water. D. Mangroves expose their roots above the sea water. 36-37. Study the diagram below. Shrimp Mangrove Heron Hermit crab Mangrove swamp Ecosystem 36. Which of the following is the producer in the diagram above? A. Mangrove B. Shrimp