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Environmental Science and Policy Final


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What particular properties of water are imortant to understand it's disposition and transport?
1) Hyrdogens are covalently bonded to oxygen
2) This creates charge assymetry
(oxygen negative, hydrogen positive)
3) Makes it an effective solution for molecules with a negative or positive charge
4) Liquid water - molecules bind by hydrogen bonds to form complex chains
5) Liquidity leads to extent of chains temperature dependent - water reaches maximum density (weight/volume at 4 degrees C)
6) Contribute to water's high heat capacity - water slow to heat up
7) At zero degrees hydrogen bonds form a crystal lattice
How are hyrodgens bonded in H20?
What is created by the bonds in H20?
a charge assymetry, which creates an effective solvent for molecules with either a positive or negative charge
Who does wate form at zero degrees? What does this lead to
a crystal lattice. a lower density for frozen water.
Where is evapotransportation highest?
where precipitation and runoff are lowest
Where are the most water demanding activities?
Often sites of greatest water deficits
What is el nino/la nina southern oscillation? What effect does this have and where?
shifts in equatoral Pacific Ocean temperatures. Affect evaporation and available water transport to SW United States.
What chemicals have significantly increased their concentrations in water?
SO2 and NOx
What do SO2 and NOx become in water?
Nitric and sulfuric acid
What factors determine soil permeability?
1) soil permeability
2) saturation
3) slope
4) vegetation - leaf area
What are the impacts of surface runoff?
1) Vegetation alteration
2) Impermeable surfaces
-alter flows
-significant impact on chemistry
Why do lakes have a short life span in geological time?
What is the difference between open and closed basin lakes?
Open basin lakes have liquid inflow and outflow, while closed basin lakes lack liquid outflow.
What happens in closed basin lakes?
Water is lost to evaporation, which leaves salts concentrated
What are the primary effects of dams?
Sedimentation and changes in patterns of flow
Explain how wetlands are an environmental asset?
1) Slow and dampen variability in surface flows
2) Absorb and retain sediments and dissolved materials
Explain the patterns of water flow in estuaries and bays.
1)Surface waters moving seaward
2)Deep waters flowing backwards, towards source
What is an effect of the complex pattern of water flows of estuaries and bays?
Long residence times allow accumulation of nutrients and pollutants.
What are some methods of sustainable freshwater management?
1) Decrease agricultural demand
2) Make more of it - desalination
3) Reduction of municipal and industrial demand (lawns, waste water recycling, etc).
What are some current issues that are important to estuaries and bays?
1) Salinificaiton
2) River eutrophication/dead zones
Explain soil structure. What are the four layers?
Residual soils weather in place from parent rock and develop distinct horizons. O-horizon, A-Horizon, B-horizon, and C-horizon.
What is the O-Horizon?
mostly organic humus - decomposing plant material
What is the A-Horizon?
topsoil is an intermingling of weathered mineral material and organic matter - high activity by decomposing organisms and lots of nutrients
What is the B-Horizon?
Often leached of nutrient material but retains water
What is the C-Horizon?
Transition to the parent rock
What are transported soils?
Eroded materials redeposited from elsewhere.
What are the five properties of soil?
1) Texture
2) Organic matter content
3) Water and nutrient holding capacity
4) Tilth
5) Loam
What is soil texture? What are the three categories from largest to smallest?
Refers to the size of soil particles? Sand is the largest, then silt, and finally clay.
Why are sand particles so large?
They are poorly weathered
What has happened to silt particles?
They have been chemically altered
What are three properties of clay?
1)highly weathered
2)chemically reactive
3)retains nutrients on electrically charged surfaces
What effect does organic matter content have on the soil?
It has an effect due to its charged particles which hold nutrients
What is correlated to the water and nutrient holding capacity of soil?
Organic matter, silt, and clay
What is tilth?
Refers to the crumb structure of soil that allows it to retain water and nutrients, while providing aeration and water percolation.
What is loam?
Soil with a balanced texture and adequate organic matter
What are the three factors that affect agricultural production?
1) Water
2) Nutrients
3) Competitors - diseases and pests
What are the five "Green Revolutions"?
1) irrigation
2) fertilizer
3) biocide
4) plant and animal breeding
5) genetic engineering
Where is demand greatest for irrigation?
Where supply is least
What happens in areas that there is great demand for water, but little local supply?
Salinization due to evaporation
What is desertification?
agriculture and grazing into marginal areas leading to permanent conversions to desert
What was the silent spring and what chemical did it relate to?
the DDT biocide.
What are the 3 current focuses on biocide development?
1)Increased specifity
2)High biodegradability
3)Application management
What is the current concern about plant and animal breeding?
People are concerned that breeding in many crop species has resulted in loss of genetic variability that may be important for the future.
What happens in genetic engineering of plants?
Genes coding for special traits in one organism can be inserted in genome of another
What is the BT toxin used for and what concenrs are there?
BT toxin is a genetically engineered addition to corn. Concerns arise about gene and toxin escape, while the larvae develop a resistance.
What are five strategies for sustainable argiculture?
1) Contour farming
2) No till agriculture
3) Mixed species agriculture
4) Organic farming
5) Integrated pest management (IPM)
What are some strategies to feed an increasingly hungry world?
1) Use more land?
2) Greater efficiency
3) Biotechnology
4) Eat lower on the food chain
What two factors have caused the increase in C02 emissions?
1) Burning of fosil energy
2) Deforestation
Why does the increase in C02 matter?
1) It limts nutrient to plant growth
2) C02 coupling to atmospheric pressure (global warming)
3) Thermal expansion of ocean
4) Melting of glacial ice
About what percent of the world's NPP do humans use?
What are the 11 methods/sources for creating energy?
1) Extraction from biomass
2) Biofuels
3) Coal
4) Petroleum
5) Nuclear
6) Hydrogen fuel cell
7) Water
8) The energy of tide and waves
9) Geothermal energy
10) Wind
11) Solar
What are the primary sources for energy for much of the world?
Fuel wood and charcoal
What are two types of biofuels and what are the upsides and downsides to these fuels?
Ethanol and methanol. Upside - its renewable, no net carbon emission from the source of the fuel.
Downside - controversey over EROI (some think 65%)
What's the world's most abundant fossil fuel?
What creates coal?
Fossil material laid down in swampy environments millions of years ago
What are the three types of coal, list them in order of heat content.
What are the concerns about use of coal?
1) Coal extraction
2) Energy content/volume low
3) Emissions from coal-fired plants
What has been considered as a strategy to mediate some of the concerns?
Coal gasification
What does oil originate from?
The remains of marine algae and bacteria
What do the remains that create coal decompose to? What is this material?
Kerogen, a complex mixture of hydrocarbons
What happens to kerogen under pressure?
Becomes petroleum
What sits above petroleum?
Natural gas
What percentage of oil can be found in the middle east?
How is nuclear energy created?
1) Unstalbe isotopes decay to release alpha and beta particles and high energy photons (gamma rays and X-rays), which generates a lot of heat
2) heat boils water
3) steam turns turbine to create energy
What are the environmental concerns assoicated with management of nuclear energy?
1) Mining operations present specific environmental impact and pollution
2) Spent fuel may be stored wet or dry or recprocessed and recycled
3) Stored fuel could be put in a permanent reposity removed from the biosphere
4) Reprocesse fuel could be re-used, increasing efficiency and EROI
What is the problem for creating the fuel for hydrogen fuel cells?
Need a source of and deilvery system for H2. H20 has lots, but EROI is low.
What the 3 problems associated with using water as a source of energy?
1)altered flows affect downstream ecosystems
3)fragmentation of watercourses
What are the four green energy sources that do not require extraction?
1) Water power
2) Wind power
3) Geothermal Power
4) Wave and Tidal Power
What are the two ways that solar energy is trapped?
1) passive solar traps
2) photovoltaic solar panels
What forms of energy have huamns appropriated and by what technologies?
1) Carbon-based - biomass, coal, petroleum
2) Non-carbon based - nuclear, hydrogen, water, geothermal, wind, and solar
What is the extent of human use of energy sources relative to their supply?
1) Humans co-opt 32% of Earth's NPP
2) Supply of coal is considerable
3) Supply of oil is limited - most of it is in the Middle East
4) Human's co-opt much of available energy in flowing streams
What is the work return on energy used for a particular energy source?
Hard to assess - efficiences in terms of work accomplished per energy unit available are generally less than 10%.
What environmental challenges are associated with each energy source?
There Ain't No Such Thing As A Free Lunch
What are the issues that make it complex to determine the likely future change in the use of each energy source?
1) Geographic distribution
2) National Security Challenges
3) Start-up costs
4) Human values
Based only on its molecular weight, a chemist would predict that water would boil at temperatures well below its actual freezing point. What features of water contribute to its high boiling point? How does the density of water change from freezing to boi
Because water has a positively and negatively charged portion it forms hydrogen bonds linking molecules together. Liquid water exists as strings of water molecules. At freezing, these bonds form a regular lattice structure and water has very low density (ie ice floats). As it melts, water is more dense at about 4 degrees C and then becomes less dense up to boiling. At boiling individual molecules separate and evaporate.
Explain why rainfall in many regions has become more acidic over the past 50 years. Why is this more of a concern to people in the northeastern U.S. than in the Far West?
Primary reason is emssions of sulfur dioxide (SO2) and nitrous oxid (NOx) which dissolve in water to form sulfuric acid and nitric acid, respectively. They are of concern in the Northeast more than the West because of the high emissions coming from the industrial centers.
Urban development has resulted in increasing flooding in many streams, particularly during heavy rain events. Why is this so?
This is primarily a consequence of expansion of impermeable surfaces that increase the amount of runoff compared to the percolation of water into the soil.
Water supplies in some coastal towns are becaming saliter. Why?
Freshwater floats on salt water. As water is pumped the inerface between fresh and salt water moves up, eventually intruding into wells.
Describe three important environmental consequences of the damning of streams.
Sedimentation, alteration of hydrologic flows, and fragmentation of stream habitat. (Explain each consequence)
List and describe four important factors that affect agricultural productivity. What have been the environmental consequences of human actions to cope with each of these factors?
Four factors would be soil structure, water, nutrients and competitors (see slide on Agriculture lecture). A complete answer would include a human action related to each factor and a discussion of its environmental consequences. For example, with regard to nutrients, you might discuss the importance of nitrogen fertilizers (human nitrogen fixation) and its impacts on the quality of water running off from agricultural fields.
What is soil salination and what is its cause?
Salination refers to the accumulation of salts at the surface of soils in arid regions. It occurs where irrigation water contains minerals that are deposited as salts as the water evaporates.
Although the ice cap at the North Pole appears to be shrinking, it is the loss of ice in Greenland and Antarctica that worry scientists with regard to future sea level rise. Why?
The polar ice cap floats on the Arctic Ocean. Thus, if it melts, it would not add water to the ocean (think about the melting ice cubes in your coke). Ice in Greenland and Antarctica is primarily on land and its melt-water will add to the volume of the ocean.
We say that carbon dioxide is a greenhouse gas—what do we actually mean by that (i.e., explain why more of it means warmer temperatures)?
By greenhouse gas, we are referring to CO2s capacity to absorb infrared photons. Such photons are radiated from the earth’s surfaces as they are heated up. The absorbed photon energy is translated into the kinetic energy of CO2 molecules—i.e., the atmosphere’s temperature.
Explain how a nuclear power plant generates electricity. What is the ultimate source of the energy?
The ultimate source of energy is high energy particles emitted with the decay of radioactive isotopes of certain heavy metals such as uranium and plutonium. These particles heat up surrounding molecules, especially liquids (usually water, but sometimes liquid sodium) to produce steam that is then used to drive turbines to generate electricity.
What environmental challenges does the burning of fuel wood present in many developing countries?
The two most significant challenges are impacts on forests/deforestation and very poor air quality owing to particulates and other emissions.
Describe four factors that influence the potential risk that a toxic chemical may present to people.
Duration of exposure
Genetics of exposed individuals
Age of exposed inviduals
Concentration of toxin
Mode of exposure
Each of these should be described and discussed in a few sentences.
14. What three pieces of evidence might you look for to support my claim that the forest just down slope from the Duke Chapel has been heavily influenced by the history of human land use in this area? Briefly explain each.
The dominance of pines in that forest indicates that it was once an open field. Remember that pines are unable to grow in their own shade, and this area is being overtaken by hardwoods
The presence of many non-native species (e.g., honeysuckle, privet and magnolia) which have been introduced by people.
The remnants of agricultural furrows and erosion gullies indicating that this was once a badly eroded field.
What are the laws of thermodynamics and how do they relate to the relative abundance of organisms at different trophic levels?
The first law of thermodynamics is that energy can neither be created nor destroyed, only transformed from one form to another. The second law states that in any transformation of energy, the entropy (randomness) of the universe must increase—no energy transformation is 100% efficient.
To follow, what I would expect would be an explanation of the connection to the so-called pyramid of biomass and productivity and why there are generally more producers than herbivores than carnivores.
Describe four factors that are contributing to the loss of species in many regions of the world?
Habitat loss
Habitat fragmentation
Invasive alien species
Changing patterns of disturbance
Climate change
A complete answer would require a couple sentences describing the connections between each of the above and species loss.
Why do polar regions appear to be warming faster than areas in the tropics or temperate zone?
Atmospheric circulation moves heat continuously towards the poles; this accentuates or concentrates global warming in these regions.
18. Some have argued that the rapid growth in human populations over the past century, the so-called green and industrial revolutions, and the changes in our climate are all connected. Describe those connections.
This is a pretty open-ended question. Certainly the rapid growth in populations over the past century relates in part to the increased availability of food, which in turn is related to the use of fossil energy to increase productivity of agricultural land. Burning of fossil fuels has increased the concentration of CO2 and other greenhouse gasses.
Why is the question “how many people can the world support?” so difficult to answer?
Again, not a very definite question, but primarily because the answer depends on the lifestyles we wish to support and how we deal with issues of equity and justice.
It is often the case that when countries have established national parks or nature preserves, the number of species they contain have actually declined. What is the likely cause of this decline?
Creation of parks and preserves has often resulted in the abuse of the lands that surround them, thus turning them into islands. As such, the total area of habitat actually diminishes and its connection to other habitat is diminished. Based on the Equilibrium Theory of Island Biogeography, the extinction rate increases while the immigration rate decreases and the number of species that are supported declines.
Is there a discernable pattern of recovery or change following disturbance?
Multiple patterns - some directional, others cyclical, and yet other very variable
What the mechanisms underlying change following disturbances?
Allogenic and autogenic factors
Does the pattern of change (following a disturbance) relate to disturbance size or severity?
In general, pattern depends on nature of ecosystem legaices left by disturbance.
What determines the timing and severity of disturbances?
Often determined by status of ecosystems (e.g. fuels)
May be affected by regime change
Are patterns of disturbances changing? If so, why?
changing patterns of land use
climate change
How are natural and human-caused legacies different?
Vary in rates and nature of legacies
What are the policy and management implications of ecosystem disturbance and change?
General rule of thumb - imitate nature in scale, frequency, and key legacies
What are the key conservation legislations that have passed in the US?
1) National Environmental Policy Act (NEPA 1970)
2) Marine Mamals Protection Act (MMPA)
3) Endangered Species Act (ESA 1973)
4) National Forest Management Act (NFMA 1976)
What are the six rules for conservation management?
1) Big is better than small
2) Connected is better than unconnected
3) Close is better than far apart
4) High population growth is better than low population growth
5) Low variation in population size is better than high variation
6) Complex ecosystem is better than simple
What factors influence rates of immigration and extinction on islands?
Immigration - distance to the mainland
Extinction - island size
What are the six methods of valuing biodiversity?
1) Existence value
2) Market value
3) Functional importance
4) Stability (resistance to and resilience from disturbance)
5) Genetic Diversity
6) Environmental indicators
Why are there so many species?
1)Geographic isolation
2)Niche specialization
What are three types of natural selection?
1)Stabilizing selection
2)Directional selection
3)Disruptive selection
What are the origins of biodiversity?
1) Mutation
2) Random genetic drift
3) Natural selection
What are the six measures of biodiversity/biocomplexity?
1)Biomes and Communities-biogeographic diversity: groups of organisms occur in repeatable configurations across continents
2)Species diversity/richness
3)Species evenness - the distribution of abudance of species
4)Genetic diversity
5)Functional diversity
6)Spatial and temporal complexity: the arrangement of species, genotypes, or functional types in space and time.
What are social system outputs that affect birth and death schedules that set humans apart?
1)Belief systems
What are the six strategies to reduce footprint?
1)Search for more resource efficient technologies
2)Separate the more damanging from the more benign activities.
3)Substitute the more benign for the more damaging.
4)Shrink energy and material thoroughputs.
5)Satiate some consumption needs
6)Sublimate consumption desires.
What is responsible for apparent explosive population change?
Exponential growth
What determines rates of growth?
Carrying capacity (sort of)
Birth Rate
Death Rate
Reproductive Age
What is the total fertility rate?
life time potential fertility productivity
What is the term for the average age of first reproduction?
generation time
What are the three types of feedback mechanisms for population growth?
1)Finely tuned feedback
2)Inefficient Feedback
3)Population really overshoots - resource base cannot recover
Although total fertility rate may remain constant, a shift toward a higher age to first reproduction may produce a marked change in population growth rate. What sort of change would you expect and why?
Total fertility rate refers to the total number of children an average woman in a population would have if she were to live to menopause (cessation of reproduction). It does not take into account the fact that some women will not survive that long. A shift to a higher age will slow population growth rate for two reasons. First, it lengthens the generation time, extending the time over which a woman would have children. More important, it also means that fewer women will survive to realize their full reproductive potential.
2) Draw and label a graph illustrating three characteristic patterns of population change with respect to carrying capacity, and explain how these differences arise.
Red = standard logistic growth. As resources become limiting there is a very direct feedback to birth and death rates such that growth rate decreases, smoothly approaching zero as the numbers (N) approach the carrying capacity.
Blue = poor feedback of resources on birth and death rates; growth rate remains high and population number overshoots carrying capacity. Death and birth rates eventually do respond and population numbers drop; resource recovers; growth rate recovers, etc. Green = very poor feedback of resources on birth and death rates. Population overshoots carrying capacity by such an extent that resources cannot recover. Population goes locally extinct.
Explain (illustrate) how environmental factors may interact to limit the tolerance of organisms to environmental conditions.
This question refers to fact that an organism’s range of tolerance for one environmental variable depends on the values of others. The example I used in class was the interaction between temperature and water availability. In general, an organism’s tolerance for high temperatures increases as water becomes more available. Alternatively, an organism’s requirements for water increase as temperature increases. See my lecture for a graph of this interaction.
Draw and label a graph illustrating three characteristic patterns of population change with respect to carrying capacity, and explain how these differences arise.
Red = standard logistic growth. As resources become limiting there is a very direct feedback to birth and death rates such that growth rate decreases, smoothly approaching zero as the numbers (N) approach the carrying capacity.
Blue = poor feedback of resources on birth and death rates; growth rate remains high and population number overshoots carrying capacity. Death and birth rates eventually do respond and population numbers drop; resource recovers; growth rate recovers, etc. Green = very poor feedback of resources on birth and death rates. Population overshoots carrying capacity by such an extent that resources cannot recover. Population goes locally extinct.
Define the realized and the fundamental niche. What is niche overlap and niche displacement?
The fundamental niche of an organism is the range of conditions for all of the factors in its environment over which it can potentially survive (have positive growth), taking into account interactions among these factors. The realized niche is the actual range of conditions where the organism is found. Niche overlap refers to the overlap between organisms in their fundamental niches and niche displacement refers to the effects of competition that produce the realized niche.
What is competitive exclusion? Give an example.
Competitive exclusion refers to the notion that complete competitors cannot coexist. If forced to compete, one competitor will eventually exclude the other. The example I used in class involved Gause’s classic studies of Paramecium.
How do predators benefit their prey species populations?
Predators do not generally take individuals from a population at random. Rather, they seek out the weakest animals. In general, this increases the overall health of the population.
7) Over our history as a species, important innovations have had a marked effect on populations. Name two and explain their importance.
1) irrigation
2) large scale agriculture
8) What is Thompson’s theory of demographic transitions? Describe its stages and give examples of regions of the world that might be representative of them.
Thompson’s theory is that economic development is accompanied by changes in demographic behavior that eventually slow birth rates and result in increased life expectancy with very low growth rates. The stages are:

1. Population has high birth rates and death rates—subject to fluctuation -- typical of parts of Sub-Saharan Africa today
2. Mortality transition--Improved quality of life—death rate decreases but average birth rate remains high – Countries early in economic development; examples might also include some in Africa and places like Haiti
3. Fertility transition—Death rate remains low and average birth rate declines – This is happening throughout most of Latin America
4. Both birth and death rate stabilize at low levels; population growth rate slows – Typical of some parts of western Europe such as Italy or Spain
Name and define three different measures of biodiversity.
• Biomes and Communities—biogeographic diversity: Groups of organisms occur in repeatable configurations across continents.
• Species diversity/richness: number of species in an area.
• Species Evenness: the distribution of abundance among species
• Genetic diversity: variability in genetic composition within a species or population.
• Functional diversity: variety of functional roles played by organisms within an ecosystem.
• Spatial and temporal complexity: The “arrangement” of species, genotypes or functional types in space and time.
Define and compare directional selection and stabilizing selection. What is the effect of each type of selection on genetic variation within a population?
The curves above represent a the relative abundance of individuals in a population along a gradient for a given characteristic (height, for example). The top graph is stablilizing selection where the extremes (very tall and very short) are disadvantaged. Stabilizing selection tends to preserve genetic variation in a population. The bottom graph displays directional selection in which individuals at one end of the character gradient are at a disadvantage relative to others. Without any new mutations, directional selection tends to diminish genetic diversity because it removes certain phenotypes/genotypes from the population.
You do a census of amphibian and fish diversity and find that the total number of species varies widely among ponds around the Duke campus. What factors would you expect to be important in explaining this variation in species numbers and why?
Best answer here would focus on the Equilibrium Theory of Island Biogeography, i.e., that the number of species in a location is a consequence of the equilibrium between the rates of new species arrival (immigration) and local extinction. Immigration rates will be highest for ponds that are in close proximity to a species source (e.g., other large ponds) and lowest for ponds that are isolated. Extinction rates will increase as ponds go from large to small. Thus, you would expect the greatest number of species in large, nearby ponds and the lowest number in isolated small ponds.
Describe four major threats to biodiversity on a global scale.
Here I would be looking for a bit of discussion of habitat loss, habitat fragmentation, pollution, climate change, invasive species, or changing patterns of disturbance.
Describe the pattern of change that you would expect in a typical primary succession such as following glaciation or on newly-exposed rock. What is “facilitation” and what role does it play in such patterns?
Initially invasion involves widely dispersed and hardy pioneer species which modify their environment making it more hospitable for other possible invaders. Successive invaders modify their environments facilitating the invasion of other species. Eventually a suite of species arrives that modifies the environment in such a way as to favor its own long-term persistence. This is the climax stage of succession
Ecologists are convinced that so-called “successional legacies” are important in the patterns of change following natural and human-caused disturbance. What do they mean by this phrase? Give an example and explain its importance.
Successional legacies refers to such things as soil organic matter, nutrients, woody debris, etc. that influence patterns of establishment following disturbance. An example might be the important role of woody debris and soil organic matter following a forest cutting.
What is an allele?
A version of a gene that codes for a distinct trait.
Total fertility rate
The number of children a female in a population will have if she lives through menopause.
What is a phenotype
The physical expression of the genotype.
What is an Ecological legacy
The remnants of an ecosystem that persist after disturbance and facilitate secondary succession, e.g. organic matter, debris, seed banks etc.
Compare/contrast Arithmetic growth/Exponential growth
Arithmetic growth – simple interest, constant rate of increase, linear growth.
Exponential growth – compound interest, increasing rate of growth.
What are the push/pull migration factors?
Push – factors that induce organisms (e.g. people) to leave an area, such as lack of resources, persecution.
Pull – factors that induce people to move to an area, such as resources, freedom.
If the Avian Flu (H5N1 virus) were to “jump” to human populations, what 3 factors would likely affect the rate of its spread? Describe each
Host population density
Transmissivity – how easily is virus transmitted among hosts
Virulence—if virus kills host this may limit spread
Virus life history complexity
In his Demographic Transition model, Warren Thompson described what he called the “mortality transition” and the “fertility transition.” To what do these transitions refer, and what is their cause?
Mortality transition refers to demographic shifts occurring as economic development begins. Improved sanitation, nutrition and health care result in lower death rates and higher life expectancy; birth rates remain high, may increase.

Fertility transition begins as economic conditions allow for improved education, especially for women. Women defer child bearing. Diminished need for children in work force and other factors result in need for fewer children
Name and describe 4 possible causes of the marked decline in amphibians that is worrying ecologists (and should be worrying everyone)?
1.Habitat destruction/loss
2.Habitat fragmentation
3.Increased pollution/toxins
4.Climate change
5.Increased UV radiation (remember the ozone hole from module 1?)
6.Changed disturbance patterns
7.Invasive species/disease
Chemical bonds in which atoms share electrons are said to be what?
What are chemicals that lower the activation energy of a reaction without themselves being consumed or altered.
What is the transfer of heat via the direct collision of molecules with one another called?
The most abundant molecule in the air we breathe is what?
Over the past decade, there has been much conflict among various groups over whether commercial logging should continue in the nation’s National Forests. Briefly describe the positions that you think Gifford Pinchot and John Muir would take on this iss
Pinchot was a conservationist who believed in using natural resources for human good, specifically “the greatest good, for the greatest number, for the longest time.” He would allow careful, sustainable logging in National Forests, if there was a need for it.

Muir was a preservationist, who believed in preserving nature for its intrinsic value. He would oppose logging in National Forests.
It may seem like a remarkable coincidence that plant photosynthesis responds to exactly the same portion of the electromagnetic spectrum as our eyes (visible light). Explain why biologists are not surprised by this and why they believe that organisms do
Organisms use the spectrum of visible light because it has the right amount of energy needed both to excite electrons in our eyes, and to carry out photosynthesis. Shorter wavelengths have too much energy, and are destructive to living tissue. Longer wavelengths do not have sufficient energy to carry out the reactions.
Compare and contrast exergonic and endergonic reactions and give an example of each
Endergonic reactions require an input of energy. Examples are photosynthesis and the breakdown of water to hydrogen and oxygen.

Exergonic reactions result in a release of energy. Examples are cellular respiration and the combination of hydrogen and oxygen to form water.
Describe the relationships among the following terms: absolute humidity, relative humidity, saturation humidity and dew point
Absolute humidity – actual amount of water in the air
Saturation humidity – the amount of water the air can hold at a given temperature

Relative humidity = abs hum/sat hum x 100

Dew point is the temperature at which a mass of air becomes saturated with water (rains, dew forms, etc.) {a number of you did not mention temperature here and lost a point}
Current national accounting standards used by such bodies as the World Bank and the International Monetary Fund emphasize Gross Domestic Product (GDP) as a measure of well-being. Many economists have argued that this emphasis may actually encourage the d
The primary point to be made here is that GDP increases whenever money is spent or transactions occur, even when those funds are spent on cleaning up messes (e.g., chemical spills) or on the over-exploitation of a natural resource (e.g., deforestation). GDP does not account for depreciation or depletion. {I accepted a wide variety of answers here as long as these points came through}
What are three characteristics of environmental challenges? Give an example of an environmental challenge and show how it reflects each of the characteristics you named.
⬢ The Tyranny of boundaries
⬢ Complexity
⬢ Eternal change
⬢ Uncertainty
⬢ Human values
⬢ Priorities
⬢ Taking action
What is matter composed of? Name the constituent parts of the building blocks of matter and the types of bonds that hold them together.
• Covalent – atoms share electrons example water
• Ionic – atoms are bonded by positive and negative charge example NaCl
• Van der Waals bonds – very weak bonds produced by slight variations in charge on atom surfaces example graphite
Energy takes many forms, but what exactly is it? Give the definition of energy. Then give three examples of energy in different forms, and explain a role of each form in making possible life on earth.
• Mechanical – e.g., energy in a coiled spring … I really did not discuss this much, but it is relevant to body movements in complex organisms, for example.
• Gravitational – the force exerted by every particle of matter on every other particle of matter. Quite simply it is the force that attaches us to the Earth’s surface
• Kinetic – the energy of motion, including such things as falling water and bodies in motion. Probably most important in the movement of molecules whose kinetic energy is the basis for heat.
• Electromagnetic – energy in the form of photons that are propagated as waves; shorter the wavelength greater the energy. Electromagnetic energy in the visible part of the spectrum (wavelength) fuels photosynthesis.
• Chemical – the energy in chemical bonds. Reduced carbon (e.g., sugars) possesses considerable chemical energy which is released when bonds are broken.
• Nuclear – This is the energy tied up in matter (E=MC2), for example, the energy released from the decay of unstable isotopes of particular elements. Examples of such isotopes include Carbon 14 and isotopes of uranium and plutonium. Also energy released from the fusion of elements to form new elements (e.g., hydrogen atoms fuse to form helium) as occurs in the sun.
Why is the second law of thermodynamics important to us? Use an example to illustrate your point.
Although not explicit in the question, you should begin your answer with a definition of the second law of thermodynamics: all energy transformations increase the disorder/entropy in the Universe. The implication of this law is that no energy transformation is 100% efficient and that some energy will always be lost as heat or other non-usable energy forms. An example would be our ability to transform the food we eat into our own tissue. We do this with about 1-2% efficiency (although it sure doesn’t seem that way judging by my own tendency to gain weight because of my affection for sweets); the remainder of the energy is lost as waste or heat.
Rocks are all over the place. What are two different classes of rock types and how was each formed?
• Igneous – volcanic rocks formed either from molten mantle material seeping up through the crust or from the re-melted continental crust
• Sedimentary – rocks formed from the consolidation of materials eroded from soils and rocks or laid down in wetlands, aquatic or marine ecosystems. They include such rocks as limestone, sandstone and coal.
• Metamorphic – Igneous or sedimentary rocks that have been transformed by high pressures, often in the presence of water. Metamorphic rocks include such things as granite.
How old is earth (roughly)? How old is life (roughly)? How old is life on land, and why did it take so long for life to move from water to land?
Earth = 4.6 Billion years
Life = probably about 4 billion years
Life on land = 420 million years. Movement of life onto land depended on the development of a stratospheric ozone layer sufficiently dense to filter out the destructive ultraviolet radiation from the sun. This happened when the tropospheric oxygen level rose to about 10%.
Name three types of heat transfer, and give an example of each.
Conduction – the direct transfer of heat via kinetic energy of molecules transferred to one another. That hot feeling when you place your hand on a stove top is conduction.
Convection – heat transfer that occurs as liquids or gases change in density and are caused to circulate. The rising of air over warm land sets up convection. The Hadley cell is an example of large-scale convection.
Radiation – all matter above absolute zero temperature loses energy by means of radiation of photons. The higher the temperature, the more energetic the photons. Example – you radiate warmth from your body or the red photons emitted from a very hot piece of metal.
What does the formula e=mc^2 mean? Why is it important?
Energy is equivalent to the mass times the square of the speed of light. This tells us that small changes in mass occurring in fission or fusion reactions will produce very large amounts of energy.
Why do we see the spectrum of light we do? That is, what else does light in the 400-700nm range do besides light up our world?
Photons at these wavelengths are of sufficient energy to excite electrons in the organic chemicals in our retina (eye) sufficiently to fire the optic nerve. Longer-wave photons have insufficient energy and shorter-wave photons (e.g., ultraviolet light) have too much energy (e.g., cause breakdown of organic molecules). These same wavelengths are what drive photosynthesis.
Besides the K/T meteor what has had the most effect on life on earth?
Example a simple consumer food chain.
1st trophic level - plants
2nd trophic level - herbivores
3rd trophic level - carnivores
What are the four spheres of the earth?
Asthenosphere - includes earth's core and mantel
Lithosphere -crust and uppermost layer or manle
hydropshere - earth's surface waters
atmosphere - gaseous layers extending up to 150 KM
What is activation energy?
the energy required to get a reaction going
What is energy?
capacity to do work
What is work?
force x distance
What is potential energy?
energy in a system that can be transferred to other forms of energy or can do work

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