1. Which animal is not found in the mangrove ecosystem? A snake B. chicken C. crocodile D. alligator 2. What makes up an ecosystem? A Biotic components of the environment. B. The energy flow component of a environment C. Abiotic components of the environment. D. The living organisms and the abiotic component of the environment 3. Why are coral reefs important? A. They are tourists' attractions. B. They make the water shallow. C. They are colorful rock-like deposits under water. D. They serve as the habitat, hatchery, and nursery of different marine animals. 4. Which of the following interactions is known as the survival of the fittest? A. mutualism C. competition B. commensalism D. Predation 5. These roots absorb nutrients from the rich soil or mud to nourish the tree. A Nutritive root B. prop root C. cable root D. long root 6. Which animals live on the forest floor? A Parrot B. sloth C. lion .D. eagle 7. It is composed of living and nonliving things. A community C. biotic B. abiotic D. ecosystem 8. Which organisms show commensalism? A. Orchids on the tree C. Fish living corals B. Barnacle living on a whale D. Sea urchin eating corals 9. In which layer of the rainforest will you find a sloth? A. Canopy B. understory C. Forest floor D. emergent 10. In a coral reef ecosystem, clown fishes, and sea anemones live together. What type of relationship do they have? A. commensalism B. Parasitism C. mutualism D. predation​