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55 Cards in this Set
- Front
- Back
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what changed during the agricultural revolution |
Transformation from hunter gather to settled and living off agricultural |
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What are the pros and cons of the green revolution |
Pros: limited deforestation, average yield increased, helped feed the starving Cons: Monocultures, pollution because of pesticides, pest became resistant to pesticides |
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What are the cons of moncultures |
Susceptible to pathogens and insects Narrows human diet |
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What are the three major problems contributing to anincreased demand for food |
Increasing human population Soil degradation Increasing wealth |
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Name two forms of protein-energy malnutrition |
Kwashiorkor- low protein Marasmus-calories and protein |
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Why is it hard to expand the cultivated land used for farming |
the planet has a limitedamount of “good” farmland |
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What are the limitations to reducing post-harvest losses |
Limitations: Spoilage with shipping, and pests can solve this with refrigeration and storage |
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Goals and limitations to inter cropping |
Goals: prevent spread of pathogens and insects Limitations: a lot more effort/labor |
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Goals and limitations to GMOs |
Goals: Create more food limitations: pollution from pesticides, health risks |
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Name the three major strategies that GM-crops havebeen applied to and the examples of them |
Reducing losses from insects, ex BT corn has gene that kills pests Reducing competition with weeds, ex soybeans with a gene resistant glyphosate Improving quality for humans, ex golden rice with added Vitamin A |
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Define Toxicology |
the study of toxins andtheir effects on living systems |
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what makes a substance a toxin |
cancause harm to tissues or organs away fromthe site of contact |
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Explain Dose-timerelationship |
the amount ofthe chemical (dose) and the duration ofexposure (time) |
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Define Acute toxicity |
one-time exposure to a large amount ofthe substance |
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Define Chronic toxicity |
repeated low-dose exposures over along time |
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Explain route of exposure |
How the chemical gets into the body |
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Explain species exposure |
Different toxins effect different species |
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Explain individual exposure |
Everyone responses differently to a chemical |
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Explain solubility |
How the chemical can move in the environment and how long it stays |
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Explain how long a watersoluble toxin will stay compared to a water-insolubletoxin |
Water soluble moves easily water-insoluble do not move easily, stay in system longer |
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What is the difference in bioaccumulation and biomagnification |
bioaccumulation- how one organism accumulates toxins over time biomagnification- how toxins move when organisms are consumed |
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Define Mutagen, teratogen, and carcinogen |
Mutagen: agents that damage or alter the DNA of a cell Teratogen: cause abnormalities during embryonic development carcinogen: substances that cause cancer |
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Define Neurotoxins, Asphyxiants, Endocrine disruptors |
Neurotoxins- chemicals that attack nerve cells Asphyxiants- chemicals that deprive tissues of oxygen Endocrine disruptor- chemicals that disrupt normal hormone function |
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how does the LD50test determine the acutetoxicity of a substance |
The LD50 of a chemical tells how muchof a substance is required to kill 50% ofa population of animals exposed to it |
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What is a threshold and a sub-threshold |
Threshold: shows when symptoms are first detected sub-threshold: shows the level of a toxicant and maximum effect |
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Define Risk assessment and what it is influenced by |
the estimationof the chance a hazard will causeharm and the severity of that harm influence by public awareness, control, degree of harm, and risk tradeoffs. |
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How does persistence ofa compound influences degration. |
Low persistence, degrade rapidly High persistence, degrade slowly (Persistent organic pollutants, POPs) |
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Explain the features of DDT |
Insecticide (intentionally used) Bioaccumulates and biomagnifies |
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Explain the features of PCB's |
Not intentionally released Low electrical conductivity, High resistance to heat Toxic at low levels Accumulate in fatty tissues (liver, kidneys, heart, lungs, brain, andbreast milk) |
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Explain the features of BPA |
can leak out of plastics endocrine disruptor |
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Explain the features of Dioxins |
never beenintentionally produced released into the air when industrial wastes are incinerated teratogenic,carcinogenic & endocrinedisruptors |
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Explain the features of Asbestos |
used to reinforce materials because oftheir resistance to fire the tiny fibers that are suspended inair and inhaled |
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Explain the features of Lead |
Attacks the nervous system and decreases mental abilities example: ADHD, aggression, impulsivity Widely in house paint,plumbing, bullets, gas |
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What is the difference between point source water pollution and non-point source water pollution? |
Point source pollution: the release of wastes from industrial sites non-point source pollution:Comes from somewhere else, used for something else. example: Fertilizers and pesticides on farms, salt on the roads |
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What is Thermal pollution |
the result of heating water, decreasing its ability to hold dissolved oxygen example: industrial cooling |
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What is sediment pollution |
the result of eroded soil ending up in a bay or river delta, makes water hazy |
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What is Nutrient pollution |
It is from fertilizers lead to eutrophication and “dead zones” that result from hypoxic water |
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What is desalination, and why it is not a major source of fresh water |
Removal of salt from seawater to make freshwater Very expensive and requires large inputs of fossil fuel |
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how does drip irrigation help conserve water |
Targets plant by being directly over it, less waste compared to regular spray irrigation |
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how is a sinkhole is created |
By taking ground water from an aquifer |
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What are aquifers & What is groundwater. What is a water table? How are they related? |
Aquifers are the sponge-like layers of sediment and rock that are soaked in groundwater Water tables display the underground depth where rock and sediment are completely saturated with water |
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What is the difference between a closed watershed and an openwatershed |
Open watersheds are drained by rivers that eventually make their way to the ocean (amazon river) Closed watersheds are inland basins that end in inland lakes or seas (Dead sea) |
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how do impervious surfaces influence the water in a watershed |
These surfaces do not let water flow through them, guide water to watersheds |
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What is a watershed |
The area of land from which rainfall drains into a river or lake example: side of a mountain by a lake |
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What does water do when it falls ontoland? |
Evaporate, Flow, Infiltration in the soil |
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Understand how air masses normally circulate and what a thermal inversion does to change this |
Normally air becomes cooler as it moves upward allowing pollutants to be dispersed. If dense, cool air remains close to the ground, this thermal inversion results in little mixing of air trapping pollutants |
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Know the difference between a Primary pollutant and a secondary Pollutant |
Primary pollutant - is emitted directly by an identifiable source Secondary pollutant - forms as a result of reactions in the air with a primary pollutant |
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Understand what the Asian Brown Cloud is and what effect it has on local conditions like light, air quality,and rainfall. |
Because of china's rapid industrialization it caused a persistent 2-milethick layer of pollution. |
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Anthropogenic |
Industrial cities are anthropogenic sources of air pollution -Factories - Automobiles - Fuel combustion |
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Known at least three examples or natural sources of air pollution |
Volcanic eruptions release massive amounts of particulate matter and sulfur dioxide Forest fires release carbon dioxide and soot Dust storms carry dust and sand thousands of miles |
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Know what ozone is, where it is normally found, how it is formed, and what it does there |
Ozone (O3) is an extremely rare but vitally important gas found in the stratosphere. The ozone layer is created when ultraviolet light strikes oxygen molecules splitting them. The free oxygen atoms join other oxygen molecules to make ozone. |
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Know what CFC's are, where they come from, and what they do to ozone. Understand why CFC's are able to do so much damage to the ozone layer. |
CFC's are considered ozone depleting substances. Broken down by sunlight Usually are Propellants in aerosol spray cans |
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Understand what is meant by residence time |
Chlorine atoms and CFC's also have a very long residence time in the atmosphere. The same chlorine atom can repeat the reaction with up to 100,000 ozone molecules. |
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Know what the Montreal Protocol was what it was intended to do, and why it was so successful |
In response to global concerns, 196 nations signed the Montreal protocol in 1987. Agreed to cut CFC production in half by 1998. |
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Know the major source of indoor air pollution discussed in class. Radon gas & Formaldehyde |
Burn wood, charcoal, animal dung, and crop waste are the main sources of indoor pollution. Two primary indoor air health risks are cigarette smoke and radon. Formaldehyde is a VOC with well known health impacts. |
