This document summarizes key concepts about biological communities and the environment. It discusses how organisms interact through coevolution, predation, and symbiosis. It also addresses competition and how it shapes communities. Major biological communities or biomes are examined, including tropical rainforests, savannas, taiga, tundra, deserts, and temperate grasslands and forests. The document also covers issues like global change through acid rain, destruction of the ozone layer, the greenhouse effect and global warming, as well as their effects on ecosystems. Potential solutions to environmental problems through laws, taxes, education, individual actions like recycling are proposed.

1. Ch. 17 & 18 “Biological Communities & The Environment

2. I. How Organisms Interact in CommunitiesA. Coevolution–back and forth evolutionary adjustments between interacting members of an ecosystem. Ex: plants and the animals who pollinate them.

3. B. Predation-act of one organism killing another for food. Ex: Lion eating zebras, snakes eating mice1. plant defenses against animals include thorns, sticky hairs, tough leaves, prickles, and chemicals.

4. C. Symbiosis-two or more species live together in a close relationship.1. Parasitism-symbiosis that is harmful to the host organism. Ex: tapeworm in a dog or tick on a human.

5. 2. Mutualism-symbiotic relationship in which both participating species benefit. Ex: Ant on acacia tree

6. 3. Commensalism-symbiotic relationship in which one species benefits and the other is neither harmed or helped. Ex: Clown fish that lives in the sea anemone.

7. II. How Competition Shapes CommunitiesA. Competition-when two species use the same resources. Species compete for resources such as food, nesting site, living space, light, minerals, water.B. Niche-how an organism lives; its way of life.C. Biodiversity-the variety of living organisms in a community.

8. III. Major Biological CommunititesA. Climate-the weather conditions in any given area. This determines where species live. The two most important elements of climate are temperature and moisture. The farther away from the equator, temperature and moisture decrease; closer to the equator, temperature and moisture increase.

9. B. Biome-a major biological community that occurs over a large area of land.C. Seven major terrestrial biomes include:

10. Tropical rainforest-the most diverse biome home to half the Earth’s living organisms, located along the equator

11. Savanna

12. Taiga - Russia

13. Tundra

14. Desert

15. Temperate Grassland- most of the central part of the U.S. is temperate grassland

16. Temperate Forest

17. D. Three major marine biomes include:Shallow ocean water, open sea surface, deep sea waters.

18. IV. Global ChangeA. Acid Rain-caused by airborne pollutants that lower the pH of the rain. Thousands of lakes are “dying” due to low pH levels and forests are being destroyed.

19. B. Ozone layer-being destroyed by chemical called CFC’s.C. Greenhouse Effect-caused by gases such as CO2 that trap heat in the earth’s atmosphere.D. Global Warming-overall increase in earth’s temperature.

20. V. Effects on EcosystemA. Biological Magnification-the accumulation of increasingly large amounts of toxic chemicals within each level of the food chain.B. Three non-replaceable resources are being consumed or destroyed at a rapid rate:1. species of living things2. topsoil3. ground water- water trapped beneath the soil in porous rocks

21. C. Rapid growth of the human population places stress on the Earth’s ecosystem.The human population growth has caused faster extinction of animal and plant species due to:Destruction of rainforest for lumberOverhuntingPollution

22. VI. Solving Environmental ProblemsA. Methods to reduce pollution include: laws and stricter standards, taxes on polluterseducation of the public.B. Each individual can help by:recycling, using alternative means of transportation, help educate people.

23. C. Two success stories of solving environmental include:1. the Nashua RiverMassachusetts Clean Water Act of 19662. Lake Washington