IB Biology Review

1. IB Biology Review Ecology: Chapter 50

2. What do you remember from the Wissahickon Creek trips? Eutrophication Biodiversity Invasive Species Benthic Macroinvertebrates

3. 1 - D (the greater the #, the greater the biodiversity) D= n(n-1) N(N-1) Where n = total # of organisms of a particular species N = total # of organisms of all species Simpson�s Biodiversity Index

4. What is eutrophication? When too much algae grows because of an addition of nutrients to the water What happens to a eutrophied ecosytem? The oxygen-sensitive species die because 1) The excess algae uses oxygen during respiration, so they use up the oxygen 2) When the algae dies, bacteria use oxygen to break it down

5. MC-1. Introduced or �invasive� species: A. usually out-compete the native species for  available resources B. often become extremely common as they  colonize an area C. can disrupt the balance of the natural species  with which they have become associated D. B and C only E. A, B, and C are correct Correct answer: E

6. MC-2. Biological control of an invasive species of a plant would include: A. chemical pesticides B. fungicides C. a fungal disease D. a machete E. fire Correct answer: C

7. What issue does the treatment and prevention of invasive species bring up? Precautionary Principle� A guiding principle which holds that, if that effects of a human-induced change would be very large, those responsible for the change must prove that it will not do harm before proceeding. Or better safe than sorry How does the Precautionary Principle give justification for strong action against the threat posed by the Greenhouse Effect? We�re not sure if humans are causing global warming, but just incase, we better reduce the Greenhouse Effect!

8. MC-3. You are working for the Environmental Protection Agency and researching the effect of a potentially toxic chemical in drinking water. There is no documented scientific evidence showing the chemical is toxic, but many suspect it to be a health hazard. Using the precautionary principle, what would be a reasonable environmental policy? A. Establish no regulations until there are conclusive  scientific studies. B. Set the acceptable levels of the chemical conservatively  low, and keep them there unless future studies show  that they can safely be raised. C. Set the acceptable levels at the highest levels  encountered, and keep them there unless future studies  demonstrate negative health effects. D. Caution individuals to use their own judgment in  deciding whether to drink water from a potentially  contaminated source. E. Establish a contingency fund to handle insurance  claims in the event that the chemical turns out to  produce negative health effects. Correct answer: B

9. 1. Habitat2. Ecology  3. Abiotic4. Biotic5. Species6. Population7. Population  Ecology8. Community9. Community  Ecology10. Ecosystem11. Ecosystem  Ecology12. Biome13. Biosphere14. Producer15. Consumer A. Living organisms (called biota) B. Concentrates mainly on factors that affect how many individuals of a  particular species live in an area. C. The global ecosystem�the sum of all the planet�s ecosystems. This  broadest area of ecology includes the entire portion of Earth inhabited by  life: the atmosphere to an altitude of several kilometers, the land down to  and including water� bearing rocks at least 3 kilometers below�ground lakes and streams, caves, and the oceans to a depth of several kilometers. D. The study of relationships between living organisms and between organisms and their environment. E. A group of organisms of the same species who live in the same area at the same time. F. The environment in which a species normally lives or the location of a  living organism. G. Non-living (ex. temp, light, water, nutrients) H. A group of populations living and interacting with each other in an area. I. Any of the world�s major ecosystems, classified according to the  predominant vegetation and characterized by adaptations of organisms to  that environment. J. A community and its abiotic factors. K. Deals with the whole array of interacting species in a community. This  area of research focuses on how interactions such as predation,  competition, and disease, as well as abiotic factors such as disturbance,  affect community structure and organization. L. A group of organisms that can interbreed and produce fertile offspring. M. The emphasis is on energy flow and chemical cycling among the various  biotic and abiotic components. N. An organism that obtains it�s energy directly from sunlight or chemical energy. O. And organisms that ingest other organic matter that is living or recently killed

10. MC-4. Which of the following levels of organization is arranged in the correct sequence from most to least inclusive? (Inclusive means that is contains more different types of organisms.) A. community, ecosystem, individual, population B. ecosystem, community, population, individual C. population, ecosystem, individual, community D. individual, population, community, ecosystem E. individual, community, population, ecosystem Correct answer: B

11. MC-5. A population is correctly defined as  having which of the following characteristics? I. inhabiting the same general area II. individuals belonging to the same species III. possessing a constant and uniform density  and dispersion A. I only B. III only C. I and II only D. II and III only E. I, II, and III Correct answer: C

12. MC-6. Probably the most important factor(s) affecting the distribution of biomes is/are: A. wind and water current patterns B. species diversity C. community succession D. climate E. day length and rainfall Correct answer: E

13. What are the biomes?

14. The moisture and temperature on the biomes chart are examples of what ecological device/term (in the vocab)? Name a few others. Abiotic factors Light, soil pH, mineral nutrients in the soil, breeding sites, territory, wind, water currents What are the opposite of abiotic factors? Name a few. Biotic factors. Predation, competition, population density, food supply, waste pollution, disease

15. MC-7. Important abiotic factors in ecosystems include which of the following? A. temperature B. water C. wind D. A and C only E. A, B, and C Correct answer: E

16. MC-8. Which of the following are important biotic factors that can affect the structure and organization of biological communities? A. precipitation, wind B. nutrient availability, soil pH C. predation, competition D. temperature, water E. light intensity, population density Correct answer: C

17. 1. Outline the consequences of releasing excess fertilizer or raw sewage into a river or stream. (6 marks) Causes eutrophication of water which is overfertilization; These excess nutrients increase algal/plant growth This leads to the death of excess algae/plants; Then bacteria decompose of algae/plants This causes an increase in decomposer bacteria; These bacteria use up all the oxygen and deoxygenate the water; This results in a decrease in population of oxygen sensitive species, thereby lowering the aquatic biodiversity;

18. 2. Temperature is an abiotic factor affecting distribution of plant species in some areas. State three other abiotic factors that affect the distribution of plant species. (3 marks) water/moisture light mineral nutrients in soil soil pH

19. 3. Explain why it is useful to use benthic macroinvertebrates populations to estimate the water quality of a body of water. (3 marks) Chemical data only relevant to the time period sample was taken Benthic macroinvertebrates respond to cumulative effects of chemicals, oxygen levels, etc. Chemical data does not reveal effect of pollutants on ecosystem. Benthic macroinvertebrates do: sensitive organisms respond to pollution first, then moderately sensitive, then less sensitive

20. 4. Explain the factors that affect the distribution of terrestrial (land) animal species. (5 marks) breeding sites � animals must breed and may need a special site; food supply � may feed on specific foods / abundance; territory � need to establish / defend for food/mates; predation � can reduce the range of another species / be reduced by predation; temperature/climate � need the proper range for survival; water � need water to live in (aquatic) / proper amount for bodily functions; free of pollution/toxic substances - could cause death;

21. 5. In communities, groups of population live together and interact with each other. Outline the importance of plants to populations of other organisms in a community. Light is the initial source of energy for almost all communities; Plants absorb light and use it in photosynthesis; Plants produce food/ organic matter for consumers; Plants produce oxygen which is need for cell respiration by many organisms Plants are the main producers in most communities; Energy flows along food chains/ webs from plants; First order consumers eat plants/ producers; Second order consumers eat first consumers that have eaten plants/ producers;