ence 5. How is the forest ecosystem affected when trees are cut down? a. Nutrients are lost in the soil. b. Oxygen will no longer be available for everyone. c. Animals who depend on forests lose their shelter and food. d. There will be available space for humans in building houses and other infrastructures. 6. The environmental conditions that keep a population from increasing in size and help balance ecosystems is called a. limiting factor b. biotic factor 7. What does eutrophication mean? a. Forests are cleared to make the land available for other purposes. b. People collect, capture, or harvest marine organisms such as coral reefs, fish, sea turtles, and others in a large quantity. c. The weakening or death of trees caused by Nitrogen Oxides (NOx) and Sulfur dioxide (SO₂) that reacts with water, oxygen, and other chemicals in the atmosphere. c. abiotic factor d. environmental factor d. An increase of organic nutrients brought about by the chemicals and garbage thrown into the bodies of water which stimulates the growth of algae and in turn, lessens the available oxygen for other aquatic animals. 8. Biodiversity is a short term for a. biological diversified b. biological diversity c. biological diverse d. bio diversified 9. Biodiversity and the survival of ecosystems has a direct proportional relationship. This means that if biodiversity will increase, the chance of survival will also a. decrease c. increase then decrease b. increase d. cannot be determined 10. The main source/s of oceanic pollution is/are a. oil, ozone, methane b. detergent, nitric oxide, oil 11. Which of the following is the major cause of wildlife depletion? a. pollution c. overfishing b. deforestation d. eutrophication c. petroleum, oil, detergent d. plastics, volcanic ashes, nitric oxide​