SCSC 105 Exam 2 Questions And Answers

What are the top 3 myths about organic production? Briefly describe each. correct answer: 1. Organic production doesn't use pesticides 2. Organic is healthier 3. Organic farming is better for the environment Organic production doesn't use pesticides correct answer: "Organic" doesn't mean non-toxic or safe. There are other pathogens associated with organic production. Organic is healthier correct answer: Not backed by scientific data. No evidence for any differences in content of over 15 nutrients. Organic farming is better for the environment correct answer: Switching to all organic production would be destructive to many ecosystems. Define ecosystem. What are the components of an ecosystem? correct answer: Collective function of organisms and their environment. Components: Food chains Nutrient cycles Plant succession Competitive exclusion Diversity Name 5 different functions that ecosystems provide. correct answer: Wildlife Food production Recreation Water regulation Raw materials What are agroecosystems, and how do they differ from ecosystems? correct answer: Ecosystems modified to produce, food, fiber, and shelter. Agroecosystems are the foundation of human societies and most ecosystems have been affected by human activity. What are ecological pyramids, and how do they help us understand biological magnification? correct answer: Transfer of energy and biomass from producers to consumers. Only about 10% of energy and biomass are transferred to the next level. What is plant succession? Give an example. correct answer: Natural changes in plant community over long periods of time. ex: when agricultural fields are abandoned, the natural ecosystem regenerates. Describe the differences and/or similarities of natural ecosystems compared to agroecosystems in terms of diversity, inputs, management, breeding, and nutrient loss. correct answer: Natural ecosystems: Nutrient cycles are in balance. Nutrients not lost unless cycle is disrupted.