Insecticide   A chemical that is used to kill insects.

Integrated waste management   The use of several options for the handling solid wastes. This includes recycling, waste reduction, composting, landfilling, and others.

Intrinsic value   An idea that things are valuable, without  “$$” value, just for there their own being.

Keystone species   An organism that is absolutely necessary for the survival or many other species.

Kinetic energy  Refers to energy in motion.

K strategist   A reproduction approach where an organism has few offspring, are born at one time, and then young are carefully cared for. This is typical of mammals and birds.   Also see R strategist.

La Nina   A major climatic phenomenon characterized by intense easterly trade winds in the eastern equatorial Pacific Ocean. It results in extensive disruption of weather around the world, often opposite to El Nino.

Lacey Act   The first national act passed in 1900 that gave protection to wildlife by forbidding interstate commerce in illegally killed wildlife.

Landfill   A site where wastes (municipal, industrial, or chemical) are disposed of and sealed in large under or aboveground cells.

Land subsidence   The phenomenon where land gradually sinks, due to excessive removal of ground water or oil.

Law of Limiting Factors   Also known as Liebig's Law of Minimums. An ecosystem can be limited by the absence or minimum amount of any one vital factor.

LD 50   Stands for lethal dose 50%, where ½ of organisms are killed due to an application of a pollutant.  

Leachate   The mixture of water and materials that are leaching (moving) through the ground. Typically pertains to the landfills.

Legumes   A group of land plants that have the ability to fix nitrogen. Examples include, peas, beans, alfalfa and clovers.

Limiting factor   A single factor that an organism must have for survival, regardless of how much of the other resources are present.  For example O_2.

Limits of tolerance   The absolutes extreme of any factor, e.g., temperature or pressure that an organism can tolerate, before it will die.  

Population Ecology

• Demography – Keeps track of human populations. The data collected is used to show age structures (number of people in various age brackets), and is separated by gender (male and female). Population profiles (graphs) are used to determine age structures (proportions of people in each age bracket), and are used to make predictions of future population trends.  The age structure histogram on the right shows the percentage of population for both male (left) and female (right) for three nations, Mexico (rapid growth), U.S. (slow growth) and Sweden (zero growth).  The shaded areas on each graph show people in their child bearing years. 

• Birth and death rates – The birth rate refers to the number of live births per thousand in a given year, while the death rate is the number of deaths per thousand in a given year.
  
• Exponential growth – is extremely rapid growth. The human population is currently experiencing exponential growth. Birth rates FAR outnumber death rates. From the first humans on earth to the early 1800’s human population increased very slowly. By 1830 the population reached 1 billion. In the next 100 years, the human population doubled to 2 billion and by 1975 (only 45 years later), the human population had doubled again to 4 billion. In 1999, world population reached 6 billion and is growing at a rate of 80 million per year. When an exotic species is introduced into an area other organisms experience exponential growth.  The lack of natural predators and abundance of resources explain this rapid growth.

Nitrogen Cycle - The nitrogen cycle involves many important forms of nitrogen, as well as bacterial organisms. Nitrogen is critically important in forming the amino acids, which in turn form proteins. The chief source of nitrogen is the atmosphere, containing about 78%. Nitrogen gas (N₂) in the atmosphere is composed of two nitrogen atoms bound together with a triple covalent bond. This makes N₂  a very non-reactive gas; it takes a tremendous amount of energy to break the bonds of a nitrogen gas molecule. Nitrogen gas can be taken from the atmosphere (or fixed) in two basic ways: 1) lightning which produces enough energy to break the triple covalent bond, and change it into the form of nitrate (N0₃) and 2) nitrogen fixation through bacteria, which use special enzymes fix nitrogen.

These nitrogen-fixing bacteria come in three forms:

1.        Those free-living in the soil, some of which form symbiotic, (mutualistic) associations with the roots of bean plants and other legumes

2.      Rhizobial bacteria

3.      Photosynthetic cyanobacteria (blue-green algae) which are commonly found in water.

All of these bacteria fix nitrogen, which means they change atmospheric nitrogen into forms that plants can use. Most plants can take up nitrate and convert it into amino acids. Animals acquire all of their amino acids when they eat plants (or other animals). When plants or animals die (or release waste) the nitrogen is returned to the soil. The usual form of nitrogen returned to the soil in animal wastes or in the output of the decomposers, is ammonia. Ammonia is rather toxic, but fortunately there are nitrifying bacteria in the soil and in the water to take up ammonia and convert it to nitrite (N0₂).  Nitrite is also somewhat toxic, but another type of bacteria, nitrate bacteria, take the nitrite and convert it to nitrate (NO₃), which can be taken up by plants to continue the cycle. Additionally, there are denitrifying bacteria, which take the nitrate and combine the nitrogen back into nitrogen gas.

Nitrogen Cycle

Environmental Laws

Regional – Each state, county and city set their own policies, so there are thousands of regional laws are on the books, too many to include here. 

National - see below:

• The Endangered Species Act (ESA) -  of 1973 passed by Congress, protects both endangered and threatened from killing, trapping, uprooting (plants) or engaging in commerce (world wide) of either parts or species. The Act requires the U.S. Fish and Wildlife Service to draft recovery plans for protected species. Habitats must be mapped and a program for preservation and management of critical habitats must be implemented so that species can rebuild their populations. The ESA was reauthorized in 1988.
  

• Lacy Act – passed by Congress in 1900, forbids interstate commerce to deal in illegally killed wildlife. This made it difficult for hunters to sell their kills.
  

• Animal Damage Control (ADC) – Now called Wildlife Services, removes nuisance animals by trapping, killing, poisoning, and other methods. This service is very controversial.
  

• Rivers and Harbors Act- of 1899, protects national waters to promote commerce.
  

• The Clean Water Act – of 1972, protects waterways from any physical, chemical, and biological activity that lowers water quality. Businesses and individuals must have permits and meet federal standards for any discharge. Billions of dollars were provided for sewage treatment facilities. 
  

• The Clean Air Act – of 1970, 1977, and 1990 established ambient standards for four primary pollutants: sulfur dioxide, particulates, carbon monoxide, and nitrogen oxides. Amended from the Air Quality Act of 1967, in 1970, 1977, and 1990, the Clean Air Act (CAA) was originally enacted to protect the quality of the Nation's air resources and the public health and welfare. The second purpose of the CAA is to initiate a research and development program to achieve the prevention and control of air pollution. Third, the act provides means for technical and financial assistance for State and local governments so that they may carry out air pollution prevention and control programs. The final goal of the CAA is to encourage the development of regional air pollution prevention and control programs.

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Sample Chapter 3 Laboratory Page

2.  Earth Science - plate tectonics and its relation to volcanism and earthquakes

a.       Be able to read a seismogram (S & P waves). Below is a description of an S (shear) wave and a P (compress ional) wave. Notice that the S wave is up and down and the P wave is side to side.

The seismogram below shows a tremor that occurred on June 26, 1994. There were three small earthquakes located in Berkeley, California, which were recorded by the BDSN station MHC at a distance of 86 km from the epicenter. The first event registered a local magnitude of 3.2 and was followed 5 minutes later by a 2.5 earthquake. Seven minutes after that, a 4.2 earthquake rattled the residents of the East Bay. The magnitude 3.2 and 4.2 events are clearly visible on this image; the 2.5 event is a very low-amplitude squiggle.

Typical seismogram showing both S and P waves.

b.       Understand how volcanic eruptions affect weather patterns.

·        During volcanic eruptions large amounts of pyroclastic material explode into the atmosphere. Ash, also generated, can stay up in the atmosphere for, weeks, months, or even years. Obviously areas close to the volcano will have a higher level of ash in the air than areas that are further away. The wind direction helps determine the area that will receive ash from a volcanic eruption.

·        If the wind direction was to change so would the area affected by ash fall.

·        Large amounts of volcanic ash in the atmosphere will darken the sky during the day. This may result in temperature changes as much as 5 to 10°C cooler than normal.

c.       Relate the diversity of organisms to the theory of evolution, and explain what role plate tectonics has in this process.

·        According to the theory of plate tectonics, 225 million years ago the continents were together in one large mass called Pangaea. As the continents slowly separated, due to continental drift, habitats also changed. These changing habitats made way for a large variety of organisms that adapted to their new habitats, thus providing the earth with tremendous biodiversity.

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Sample Chapter 4 Test Page

A.P. Environmental Science Sample Exam

1.   Which of the following factors contribute to urban blight?

a.       declining tax revenue resulting from lower property values

b.       reductions in local services like garbage collection, police and fire protection and public schools

c.       increased tax rate

d.       businesses close and properties deteriorate

e.       all of the above

2.   Which of the following provide rationale for keeping forests sustainable?

a.       conservation of biodiversity

b.       moderate regional climatic conditions such as temperature and rainfall

c.       prevent mineral loss through erosion

d.       are a source of oxygen, store carbon, and remove carbon dioxide

e.       all of the above

3.  Which population profile below best describes a developing country?

a.       the population profile has a small base

b.       the profile would show a decline of the older population and a reduction in the number of children and young people

c.       the population profile shows a high fertility rate

d.       the population profile shows a low fertility rate

e.       the profile would show a decrease in the number of children and young people

4.   According to the energy flow in ecosystems the conversion of light to organic matter by photosynthesis has an efficiency of:

a.       100%

b.       87%

c.       50%

d.       less than 10%

e.       variable rate 10%-87%

5.   The "tragedy of the commons" refers to:

a.       a resource that is owned or not owned and used by many people in common

b.       restricting deforestation of rainforests by private individuals

c.       a population of common species exceeding their carrying capacity

d.       the restricting of cattle from grazing on federally owned grasslands

e.       both b and d are correct

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Sample Chapter 4 Test Comparison Page

Compare the questions that you missed to this subject index to see what areas or concepts that you are weak in.

• If you missed questions 1, 7, 23, 28, 31, 32, 45, 57, 61, 67, 72, 89, then you should review the concepts related to environmental rules and regulations, human communities and society, and environmental ethics and sustainability.
• If you missed questions 30, 34, 100, then you should review the concepts related to biodiversity, ecosystem destruction, and global changes.
• If you missed questions 2, 14, 36, 39, 42, 59, 64, 85, then you should review the concepts related to ecosystem structure and general ecology.
• If you missed questions 3, 4, 15, 26, 65, 91, then you should review the concepts related to ecosystems and how they function.
• If you missed questions 22, 23, 93, then you should review the concepts related to population ecology and ecological succession.
• If you missed questions 6, 8, 13, 41, 50, 73, 74, then you should review the concepts related to changes in ecosystems, natural selection, plate tectonics, environmental genetics, and evolution.
• If you missed questions 3, 9, 10, 16, 29, 71, 82, 88, 94, 98, then you should review the concepts related to human demographics and populations, comparisons of developing and developed countries.
• If you missed questions 18, 25, 33, 66, 70, then you should review the concepts related to geotechnical science (soils).
• If you missed questions 6, 35, 38, 52, 54, then you should review the concepts related to water environmental quality.
• If you missed questions 55, 84, then you should review the concepts related to food production.
• If you missed questions 24, 27, then you should review the concepts related to biodiversity of the world’s wild species of animals and plants.  

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Sample Exam Answer Key & Rationale Page

A.P. Environmental Science Sample Exam Answer Key & Rationale

1. e
Urban blight occurs when conditions within a city decline. This causes businesses to close resulting in unemployment. As the tax base declines cities can no longer afford to clean up and repair it's infrastructure, thus creating lower property values and reduction in local services.

2. e
Forest sustainability refers to the use of an intact forest and it's products. This is opposite to deforestation or clear cutting. An intact forest provides many services such as carbon storage, oxygen production, carbon dioxide reduction, biodiversity, and climate moderation. It also prevents erosion.

3. c
Population profiles may represent developed and undeveloped countries. Developed countries tend to have low fertility rates, and if the fertility rate continues to be low over a period of time, then the profile will show an increased older population with a declining population of children and young people.

4. d
Primary production within ecosystems is a very inefficient process, capturing only about 2% of the solar radiation from the sun. Even though this is a small fraction of the energy available it still accounts for a very large amount of energy produced.

5. a
The "tragedy of the commons" refers to a resource that may or may not be owned, but is used by many people. Examples of this include: private ranchers using federally owned grasslands or commercial fisheries using the open ocean. This concept of tens leads to the exploitation of these common resources and typically causes a decline or destruction of these resources.  

Sample Chapter 5 Matching Questions Page

Chapter 5 A.P. Environmental Science Matching Questions Test

On your exam you may encounter multiple-choice questions that include graphs, diagrams, data, matching etc. The following practice test includes examples of this type of question; they will be incorporated into the multiple-choice section of 100 questions. There are 50 sample questions to test your knowledge. Use the answer sheet to mark your answers and the answer key to check your answers, and review the concepts that you missed. USE THE ANSWER SHEET IN THE APPENDIX AT THE BACK OF YOUR STUDY GUIDE! Good luck! 

Use the population histograms below to answer questions 25-28.

25.  Diagram A represents:
the world population projection

a.         the age structure in a  developing country

b.         the age structure in a developed country

c.         age structure of India

d.         the population of a developing country that is changing into a developed country

26. Diagram B represents:

a.         the world population projection

b.         the age structure in a  developing country

c.         the age structure in a developed country

d.         age structure of India

e.         the population of a developing country that probably will be a developed country in the future

27. Referring to Diagram B, in 25 years:

a.       there will be a large number of elderly people    c.  there will be a large number of new borns

b.       there will be a small number of elderly people    d.  it is impossible to determine population the population is rapidly expanding                                       trends with only one graph

28.  Referring to Diagram B, in 25 years:

a.       there will be a decrease in the population

b.       there will be a decrease only in the younger population

c.       the population is expanding and represents a typical developing country

d.       there will be little to no change in the population

e.       it is impossible to determine population trends with only one graph

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Sample Chapter 6 Free Response Questions Page

Chapter 6 A.P. Environmental Science Free Response Practice Test Questions

2.  Sewage (Wastewater) Treatment policies require local utilities to treat their wastewater before it is discharged into the environment.  Below is a flow diagram of a typical wastewater treatment facility.

a.         Identify and describe the components in the diagram.  Include a description and function of each component.  Explain each treatment process in terms of:

§         BOD before and after each process

§         percent removal of organic solids

b.          Explain possible uses for the materials produced as a result of the treatment process.

c.          Cite and explain two environmental policies that would affect wastewater treatment facilities.

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Sample Chapter 6 Free Response Answer Page

2.) Sewage is the wastewater released by residences, businesses and industries in a community. It is 99.94 percent water, with only 0.06 percent of the wastewater dissolved and suspended solid material. The cloudiness of sewage is caused by suspended particles, which in untreated sewage ranges from 100 to 350 mg/l. A measure of the strength of the wastewater is biochemical oxygen demand, or BOD₅. The BOD₅ measures the amount of oxygen microorganisms require in five days to break down sewage. Untreated sewage has a BOD₅ ranging from 100 mg/l to 300 mg/l. Pathogens or disease-causing organisms are present in sewage. Coliform bacteria are used as an indicator of disease-causing organisms. Sewage also contains nutrients (such as ammonia and phosphorus), minerals, and metals. Ammonia can range from 12 to 50 mg/l and phosphorus can range from 6 to 20 mg/l in untreated sewage.

a)  See the wastewater plant diagram below for important process identifiers and read on for descriptions:

·                    Sewage treatment is a multi-stage process to renovate wastewater before it reenters a body of water, is applied to the land or is reused. The goal is to reduce or remove organic matter, solids, nutrients, disease-causing organisms and other pollutants from wastewater. Each receiving body of water has limits to the amount of pollutants it can receive without degradation. Therefore, each sewage treatment plant must hold a permit listing the allowable levels of BOD₅, suspended solids, coliform bacteria and other pollutants. The discharge permits are called NPDES permits, which stands for the National Pollutant Discharge Elimination System.

Preliminary Treatment

·                    Preliminary treatment to screen out, grind up, or separate debris is the first step in wastewater treatment. Sticks, rags, large food particles, sand, gravel, toys, etc., are removed at this stage to protect the pumping and other equipment in the treatment plant. Treatment equipment such as bar screens, comminutors (a large version of a garbage disposal), and grit chambers are used as the wastewater first enters a treatment plant. The collected debris is usually disposed of in a landfill.

Primary Treatment

·                    Primary treatment is the second step in treatment and separates suspended solids and greases from wastewater. Wastewater is held in a quiet tank for several hours allowing the particles to settle to the bottom and the greases to float to the top. The solids drawn off the bottom and skimmed off the top receive further treatment as sludge. The clarified wastewater flows on to the next stage of wastewater treatment. Clarifiers and septic tanks are usually used to provide primary treatment.

Secondary Treatment

• Secondary treatment is a biological treatment process to remove dissolved organic matter from wastewater. Sewage microorganisms are cultivated and added to the wastewater. The microorganisms absorb organic matter from sewage as their food supply. Three approaches are used to accomplish secondary treatment; fixed film, suspended film and lagoon systems.

§         Fixed Film Systems - Fixed film systems grow microorganisms on substrates such as rocks, sand or plastic. The wastewater is spread over the substrate, allowing the wastewater to flow past the film of microorganisms fixed to the substrate. As organic matter and nutrients are absorbed from the wastewater, the film of microorganisms grows and thickens. Trickling filters, rotating biological contactors, and sand filters are examples of fixed film systems.

§         Suspended Film Systems - Suspended film systems stir and suspend microorganisms in wastewater. As the microorganisms absorb organic matter and nutrients from the wastewater they grow in size and number. After the microorganisms have been suspended in the wastewater for several hours, they are settled out as a sludge. Some of the sludge is pumped back into the incoming wastewater to provide "seed" microorganisms. The remainder is wasted and sent on to a sludge treatment process. Activated sludge, extended aeration, oxidation ditch, and sequential batch reactor systems are all examples of suspended film systems.

§         Lagoon Systems - Lagoon systems are shallow basins which hold the waste-water for several months to allow for the natural degradation of sewage. These systems take advantage of natural aeration and microorganisms in the wastewater to renovate sewage.

Final Treatment

§         Final treatment focuses on removal of disease-causing organisms from wastewater. Treated wastewater can be disinfected by adding chlorine or by using ultraviolet light. High levels of chlorine may be harmful to aquatic life in receiving streams. Treatment systems often add a chlorine-neutralizing chemical to the treated wastewater before stream discharge.

§         Waste sludge as a result of the final treatment could be used as fertilizer because it is rich in organic compounds, and is no longer pathogenic.  This would save additional space in landfills.

§         Treated wastewater could be sold to power companies to use in the production of electricity.

§         Treated wastewater could be used as irrigation.

§         Treated wastewater could be used to supply wetlands with water during dryer months.

Three environmental policies that affect wastewater treatment facilities are:

§         The discharge permits, called NPDES permits, stand for the National Pollutant Discharge Elimination System, state that each sewage treatment plant must hold a permit listing the allowable levels of BOD₅, suspended solids, coliform bacteria and other pollutants found in their discharge.

§         In 1972, the U.S. Congress adopted the Clean Water Act to protect the waters of the nation. Through this act, the U.S. Environmental Protection Agency and corresponding state agencies were given the responsibility to regulate activities that threaten the quality of the nation's water resources.

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