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APES Definitions
Term | Definition |
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First Law of Thermodynamics | Energy is neither created nor destroyed, but may be converted from one form to another |
Second Law of Thermodynamics | When energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat) |
Ionizing radiation | Radiation with enough energy to free electrons from atoms forming ions, may cause cancer (ex. gamma, X-rays, UV) |
High Quality Energy | Organized & concentrates, can perform useful work (ex. fossil fuels & nuclear) |
Low Quality Energy | Disorganized, dispersed (ex. heat in ocean or air/wind, solar) |
Natural radioactive decay | Unstable radioisotopes decay releasing gamma rays, alpha & beta particles (ex. Radon) |
Half-life | The time it takes for 1/2 of the mass of a radioisotope to decay. A radioactive isotope must be stored for approximately 10 half-lives until it decays to a safe level |
Nuclear Fission | Nuclei of isotopes split apart when struck by neutrons |
Nuclear Fusion | 2 isotopes of light elements (H) forced together at high temperatures till they fuse to form a heavier nucleus. Happens in the Sun, very difficult to accomplish on Earth, prohibitively expensive |
Ore | A rock that contains a large enough concentration of a mineral making it profitable to mine |
Mineral Reserve | Identified deposits currently profitable to extract |
Surface mining | Cheaper, can remove more minerals, less hazardous to workers |
Humus | Organic, dark material remaining after decomposition by microorganisms |
Leaching | Removal of dissolved materials from soil by water moving downwards through soil |
Loam | Perfect agricultural soil with equal portions of sand, silt, and clay |
Soil Conservation Methods | Conservation tillage, crop rotation, contour plowing, organic fertilizers |
Hydrologic Cycle Components | Evaporation, transpiration, runoff, condensation, precipitation, and infiltration |
Aquifer | Any water-bearing layer in the ground |
Cone of Depression | Lowering of the water table around a pumping well |
Salt Water Intrusion | Near the coast, overpumping of groundwater causes saltwater to move into the aquifer |
ENSO | El Nino Southern Oscillation, trade winds weaken & warm surface water moves toward South America. Diminished fisheries off South America, drought in western Pacific, increased precipitation in southwestern North America, fewer Atlantic hurricanes |
La Nina | "Normal" year, easterly trade winds and ocean currents pool warm water in the western Pacific, allowing upwelling of nutrient rich water off the West coast of South America |
Nitrogen Fixation | because atmospheric N cannot be used directly by plants, it must first be converted into ammonia by bacteria |
Ammonification | Decomposers convert organic waste into ammonia |
Nitrification | Ammonia is converted to nitrate ions (NO3-) |
Assimilation | Inorganic N is converted into organic molecules such as DNA/amino acids & proteins |
Denitrification | Bacteria convert ammonia back into N |
Phosphorus | Does not exist as a gas; released by weathering of phosphate rocks, it is a major limiting factor for plant growth. Phosphorus cycle is slow, and not atmospheric |
Photosynthesis | Plants convert CO2 (atmospheric C) into complex carbohydrates (glucose C6H12O6) |
Aerobic Respiration | Oxygen consuming producers, consumers & decomposers break down complex organic compounds & convert C back into CO2 |
Largest reservoirs of Carbon | (1) carbonate rocks (2) oceans |
Biotic/Abiotic | Living & nonliving components of an ecosystem |
Producer/Autotroph | Organisms that make their own food; photosynthetic life |
Trophic Levels | Producers - Primary Consumer - Secondary Consumer - Tertiary Consumer - Decomposers |
Energy Flow through Food Webs | 10% of the usable energy is transferred to the next trophic level. Reason: usable energy lost as heat (2nd law), not all biomass is digested & absorbed, predators expend energy to catch prey |
Primary succession | Development of communities in a lifeless area not previously inhabited by life (ex. lava) |
Secondary succession | Life progresses where soil remains (ex. clear-cut forest, old farm) |
Mutualism | Symbiotic relationship where both organisms benefit |
Commensalism | Symbiotic relationship where one organism benefits and the other is unaffected |
Parasitism | Relationship in which one organism (the parasite) obtains nutrients at the expense of the host |
Carrying Capacity | The number of individuals that can be sustained in an area |
r-strategist | Reproductive strategy in which organisms reproduce early, bear many small, unprotected offspring (ex. insects, mice) |
K-strategist | Reproductive strategy in which organisms reproduce late, bear few, cared for offspring (ex. humans, elephants) |
Natural Selection | Organisms that possess favorable adaptations pass them onto the next generation |
Thomas Malthus | "Human population cannot continue to increase. Consequences will be war, famine, and pestilence." |
Doubling Time | (Rule of 70) equals 70 divided by percent growth rate (ex. a population growing at 5% annually doubles in 70/5 = 14 years) |
Replacement Level Fertility | The number of children a couple must have to replace themselves (2.1 more developed, 2.7 less) |
Demographic Transition Model | Preindustrial stage, transitional stage, industrial stage, postindustrial stage |
Preindustrial stage | Birth & death rates high, population grows slowly, infant mortality high |
Transitional stage | Death rate (infant mortality) lower, birth rates remain high, better health care, population grows fast |
Industrial stage | Decline in birth rate, population growth slows |
Postindustrial stage | Low birth & death rates |
Age Structure Diagrams | Broad base - rapid growth; narrow base - negative growth; uniform shape - zero growth |
Most Populous Nations | (1) China (2) India |
Low Status of Women | Most important factor keeping population growth rates high |
Methods to Decrease Birth Rates | Family planning, contraception, economic rewards, and penalties |
Composition of Water on Earth | 97.5% seawater, 2.5% freshwater |
Soil Salinization | In arid regions, water evaporates leaving salts behind (ex. Fertile Crescent, southwestern US) |
Point Source | From specific location such as pipe or smokestack |
Non-Point Source | From over an area such as agricultural (farm) runoff, traffic |
BOD | Biological Oxygen Demand, amount of dissolved oxygen needed by aerobic decomposers to break down organic materials |
Eutrophication | Rapid algal growth caused by an excess of nitrogen & phosphorus |
Hypoxia | When aquatic plants die, the BOD rises as aerobic decomposers break down the plants, the DO drops & the water cannot support life |
Primary Air Pollutants | Produced by humans & nature (CO, CO2, SO2, NO, hydrocarbons, particulates) |
Secondary Air Pollutants | Formed by reaction of primary pollutants |
Particulate Matter | Sources include burning fossil fuels and car exhaust. Effects include reduced visibility, respiratory irritation. Methods of reduction include filtering, electrostatic precipitators, alternative energy. |
Nitrogen Oxides | (NOx) Major source is auto exhaust. Primary and secondary effects include acidification of lakes, respiratory irritation, leads to smog and ozone. Reduced using catalytic converters |
Ozone | Secondary pollutant. Causes respiratory irritation and plant damage. Reduced by reducing NO emissions and VOCs |
Sulfur Oxides | (SOx) Primary source is coal burning. Primary and secondary effects include acid deposition, respiratory irritation, plant damage. Reduction methods include: scrubbers, burn low sulfur fuel |
Carbon Oxides | (CO2 and CO) Sources include burning fossil fuels, incomplete combustion. Effects: CO binds to hemoglobin reducing blood's ability to carry O; CO2 contributes to global warming. Reduction accomplished by catalytic converters, oxygenated fuel, mass transit |
Industrial Smog | Found in cities that burn large amounts of coal |
Photochemical Smog | Formed by chemical reactions involving sunlight (NO, VOC, O) |
Acid Deposition | Caused by sulfuric and nitric acids resulting in lowered pH of surface waters |
Greenhouse Gases | Most significatn: H2O, CO2, O3, methane (CH4), CFCs. Trap outgoing infrared energy (heat) causing earth to warm |
Greenhouse Effect | A vital process, required for life to exist on Earth. If accelerated, bad, leads to global warming |
Effects of Global Warming | Rising sea level (due to thermal expansion not melting ice), extreme weather, droughts (famine), and extinctions |
Ozone Depletion | Caused by CFCs, methyl chloroform, carbon tetrachloride, halon, methyl bromide all of which attack stratospheric ozone |
Effects of Ozone Depletion | Increased UV, skin cancer, cataracts, and decreased plant growth |
Municipal Solid Waste | Is mostly paper and mostly put into landfills |
Sanitary Landfill | Problems include leachate, which is solved using a liner with a collection system; methane gas, which may be collected and burned and the volume of garbage, which may be compacted and/or reduced |
Incineration | Advantages - volume of waste reduced by 90% and waste heat can be used. Disadvantages - toxic emissions (polyvinyl chloride, dioxin), scrubbers and electrostatic precipitators needed, ash disposal |
Best Solution for Waste Problem | Reduce the amount of waste at the source |
Keystone Species | Species whose role in an ecosystem is more important than others |
Indicator Species | Species that serve as early warnings that an ecosystem is being damaged |
Major Insecticide Groups | Chlorinated hydrocarbons - ex. DDT; organophosphates - ex. malathion; carbamates - ex. aldicarb |
Pesticide Pros | Saves lives from insect transmitted disease, increases food supply, and increases profits for farmers |
Pesticide Cons | Genetic resistance, ecosystem imbalance, pesticide treadmill, persistence, bioaccumulation, and biological magnification |
Natural Pest Control | Better agricultural practices, genetically resistant plants, natural enemies, and biopesticides, sex attractants |
Electricity Generation | Steam, from water boiled by fossil fuels or nuclear energy, or falling water is used to turn a generator |
Petroleum Formation | Microscopic aquatic organisms in sediments converted by heat & pressure into a mixture of hydrocarbons |
Petroleum Pros | Cheap, easily transported, high-quality energy |
Petroleum Cons | Reserves depleted soon, pollution during drilling, transport and refining, burning makes CO2 |
Coal Formation | Peat, lignite, bituminous coal, anthracite coal |
Nuclear Reactor | Consists of a core, control rods, moderator, steam generator, turbine, containment building |
Alternate Energy Sources | Wind, solar, waves, biomass, geothermal, fuel cells |
LD-50 | The amount of a chemical that kills 50% of the animals in a test populations |
Mutagen | Causes hereditary changes |
Teratogen | Causes fetus deformities |
Carcinogen | Causes cancer |
Multiple Use Public Lands | National Forest & National Resource Lands |
Moderately Restricted Use Public Lands | National Wildlife Refuges |
Restricted Use Public Lands | National Parks, National Wilderness Preservation System |
Volcanoes and Earthquakes | Occur at tectonic plate boundaries; divergent - spreading (ex. mid-ocean ridges); convergent - (ex. trenches); transform fault, sliding - (ex. San Andreas) |
Mineral Deposits | Most abundant at convergent plate boundaries |