Exam #2

Front 1

Since tropical forests typically have only a few commercially valuable trees per acre, logging operations ______?

Back 1

Do extensive damage because of road building and injury to surrounding trees.

Front 2

Although most of the world's forests are shrinking, biologists are especially concerned about tropical forest loss because ____?

Back 2

They contain such a high biodiversity.

Front 3

Today,only ____________ of forests retaintheir old-growth features.

Back 3

25% (1/4)

Front 4

Mostcommercial loggers prefer "clear-cut" harvesting because it?

Back 4

Is the most efficient, cheapest harvest method using large, fast machinery instead of costly labor.

Front 5

Theprimary aim of the U.S. Forest Service has historically been to provide for?

Back 5

Multiple Uses

Front 6

Annually,the Forest Service __________ on timber sales mainly because of the emphasis on________________.

Back 6

Loses money; building roads into forested areas.

Front 7

Economically,monoculture forestry is advantageous for the loggers because?

Back 7

It produces large quantities of a single type of tree for a particular use, (building timber/paper pulp).

Front 8

The first symptom of range overgrazing is usually?

Back 8

The disappearance of palatable vegation.

Front 9

World deserts are?

Back 9

Increasing because of logging and grazing.

Front 10

Most public rangelands are in poor condition due to?

Back 10

Overgrazing of private livestock.

Front 11

National parks are an important part of our heritage _____?

Back 11

But they are endangered by overcrowding, pollution, and in some places mining.

Front 12

While large numbers of people continue to visit National parks, the park service budget _____?

Back 12

Is chronically underfunded.

Front 13

Loggersin the timber industry objected to setting aside land to protect the spottedowl because they _____________.

Back 13

Depend on natural resources in the area of their livelihood.

Front 14

As presented in class, a promising approach to encourage conservation and preservation in developing countries is?

Back 14

Debt-for-nature swaps

Front 15

The country that claims to have the highest proportion of it's land area protected is?

Back 15

Venezuela

Front 16

Lackof protein in young children can cause ______________ and ______________occurswhen both protein and calories are lacking.

Back 16

Kwashiorkor/Marasmus

Front 17

Naturaldisasters often instigate famines, but ________________________.

Back 17

Armed conflict and political oppression almost always play a role.

Front 18

Faminesare most often serious when there is _________________.

Back 18

Drought and war together.

Front 19

Thethree crops that humans rely on for the majority of nutrients and calories are____________________.

Back 19

Wheat, rice, and maize.

Front 20

Whatis the basis of the statement that we could feed more people if we would eatgrain rather than feeding it to livestock?

Back 20

The second law of Thermodynamics.

Front 21

Thelayer of soil that is a mixture of minerals and organic material is the_______________.

Back 21

O Horizon

Front 22

Theenergy needed to process and distribute food in the U.S. is as much as _______times the amount that is used to actually farm the crops.

Back 22

5

Front 23

Contourplowing and strip farming are methods designed to ______________.

Back 23

Prevent water and soil loss.

Front 24

TheUSDA estimates ______ percent of conventionally grown foods are contaminatedwith pesticide residue.

Back 24

73%

Front 25

What is the advantage of genetically modified crops?

Back 25

All of these benefits are GMO's

Front 26

Historically,the greatest threats to human health came from?

Back 26

Pathogenic organisms.

Front 27

Parasiticworms are very common in areas where?

Back 27

Sanitation is poor.

Front 28

Hazardoussubstances ______________ while toxins are ______________.

Back 28

Are dangerous substances; poisonous substances if ingested or inhaled.

Front 29

Whencomparing the toxicity of natural and synthetic chemicals, natural chemicalsare ________ synthetic chemicals.

Back 29

On average, just as toxic as.

Front 30

What can be said about a toxic substance?

Back 30

If a substance is toxic, it's toxicity is highly dependent on its form and where it is present in the environment.

Front 31

Amongthe most important characteristics of chemicals in determining theirenvironmental risks is/are?

Back 31

All of these are correct.

Front 32

Highly persistent toxic chemicals ____?

Back 32

Retain their toxicity as they cycle through the food chain and environment.

Front 33

AnLD50 is a dose of a toxic chemical that?

Back 33

Half of the test population is sensitive to.

Front 34

Asa society, we usually focus money and attention on health risks that are?

Back 34

Most well publicized and frightening.

Front 35

Withrespect to exposure to toxins which statement is correct?

Back 35

Acute effects are the immediate results of a single exposure, chronic effects are those that are long-lasting.

Front 36

Which of the following presents the lowest lifetime risk of death to people in the US?

Back 36

Poisonous snakes.

Front 37

Whichof the following presents the greatest lifetime risk of death to people in theUS?

Back 37

Plane crashes.

Front 38

The World Health Organization regards health as primarily a matter of ________ well-being.

Back 38

Physical, mental, and social.

Front 39

Historically,which of the following considerations in setting standards for toxic exposurehas been emphasized the least?

Back 39

Information about how toxins affect natural ecological systems.

Front 40

Which of the following factors would explain the seemingly irrational behavior of a father who smokes (high risk factor for baby. while throwing away his baby's teething rings that may contain phthalates (seemingly low risk factor for baby)?

Back 40

All of these factors can lead to the relatively irrational behavior demonstrated by the father.

Front 41

Theatmospheric zone where weather events occur is the ______________________.

Back 41

Troposphere.

Front 42

Milankovitchcycles refer to _______________________.

Back 42

Changes in the Earth's orbit, tilt, and axis.

Front 43

Mostof the excessive carbon dioxide that is theorized to cause global warming isgenerated by _________________.

Back 43

Burning of fossil fuels, cement production, and burning of forests and grasslands.

Front 44

Proponentsof climate change say that given what we know about the probability of the climatechange theory, the best thing to do is ______________________________.

Back 44

Severely cut back on production of greenhouse gases.

Front 45

Primarypollutants are those that are __________________.

Back 45

Released directly in harmful forms.

Front 46

In1986, Congress established the ____________________to help inform communitiesabout toxic substances produced and handled in their area.

Back 46

Toxic Release Inventory (TRI)

Front 47

A major source of VOC's is ________?

Back 47

Plants, bugs, and termites.

Front 48

Thereare serious signs that ozone depletion may lead to ______________.

Back 48

UV-caused skin cancers and UV-caused blindness only.

Front 49

Thereare serious signs that ozone depletion may lead to ______________.

Back 49

Fish eggs die and fish populations fall.

Front 50

Climatologistshave discovered that by drilling deep into an ice sheet _____?

Back 50

They can extract ice cores samples, showing atmospheric changes over time.

Front 51

Thephenomenon where cool, dense air sits under a layer of lighter warmer air isknown as a ____________________.

Back 51

Temperature inversion.

Front 52

The most common human health response to air pollution is ____________________________.

Back 52

Inflammatory responses in sensitive tissues.

Front 53

What type of buildings and monuments are most susceptible to acid damage?

Back 53

Limestone and marble.

Front 54

___________ozone is harmful, damaging plants and human health while ozone at the _________level screens out mutagenic ultraviolet radiation.

Back 54

Tropospheric and stratosphere.

Front 55

Of the solar energy that reaches the outer atmosphere:

Back 55

All the above is true.

Front 56

As presented in class, please explain why somepeople in the U.S. are calling for an end to all logging on “federal lands”,and then identify at least two economic facts presented in class to justifyremoving logging on federal lands.

Back 56

An end to all logging on federal lands is beingcalled on because ecological services such as maintaining water supplies,recreation and supporting biodiversity, generates more revenue at lower costs.

Front 57

As presented in class,define what an old-growth forest is, and identify what percentage of forests inthe world maintain old-growth features.

Back 57

Old-growthforests are those that cover a large enougharea and have been undisturbed by human activities long enough that trees canlive out a natural life cycle. Today,only 25% of forests retain their old-growth features.

Front 58

Please identify and explain three factorspresented in class that contribute to deforestation.

Back 58

1) Logging for valuable tropical hardwoods, such as teak and mahogany.

2) Building roads to remove logs kills more trees, but even more important, it allows entry to the forest by farmers, miners, hunters, and others who cause further damage.

3) Conversion of forest into small-scale agriculture is common in many areas.

Front 59

Explain overgrazing.

Back 59

Is damage to vegetation and soil, including lossof native forage species and erosion.

Front 60

Desertification

Back 60

When land is abused by overgrazing—especially inarid areas, where once-fertile land is converted to desert.

Front 61

Rotational Grazing

Back 61

Confining animals to a small area for a shorttime (often only a day or two) before shifting them to a new location on aschedule that simulates the effects of wild herds.

Front 62

As presented in class, providethe two principle reasons why firesuppression is a controversial strategy?

Back 62

1) Recent studies suggestthat many biological communities are fire-adapted and require periodic burningfor regeneration.

2) Eliminating fire from these forests also promoteswoody debris to accumulate, greatly increasing the chances of larger, andhotter and more damaging fires.

Front 63

Historically, timber harvest companies preferthe tactic of “clear-cutting forests, where all trees are removed, regardlessof size and/or age. Please identify andbriefly explain three alternatives to clear-cutting forests presented in class.

Back 63

1) Shelterwoodharvesting, in which mature trees are removed in a series of two or more cuts.

2) Strip-cutting,in which all the trees in a narrow corridor are harvested.

3) Selectivecutting, in which only a small percentage of the mature trees are taken ineach 10- or 20-year rotation.

Front 64

As presented in class, most of the world's forests are shrinking. Biologists are especially concerned about tropical forest loss. Please identify 3 reasons why tropical forest loss are of such concern to biologists.

Back 64

A) tropical trees are the biggesttrees in the world.

B) they contain irreplaceable woodresources.

C) there are fewer remainingtropical forests than any other forest type.

D) they contain such highbiodiversity.

E) all of these are reasons that biologists areespecially concerned about tropical forest loss.

Front 65

Inclass, it was identified that the constant use of antibiotics in agricultureposes a very real risk to humans. Aspresented in class, explain the risks of overuse of antibiotics in agricultureto humans, and identify what percent of all antibiotics are estimated to beused in the U.S. on domestic livestock to promote growth.

Back 65

40-70% of all antibiotics sold in the U.S. used on foodanimals to promote growth and more efficient feed consumption. Therisk to humans does not involve antibiotic residues being found in the meat. Whatthe risk does involve is bacteria becoming resistant to antibiotics anddeveloping new strains that aren’t able to be treated with antibiotic drugs.

Front 66

Identifythe three reasons that we would benefit by using Food Labels (Nutrition Facts).

Back 66

1) Theyhighlight information on saturated fat, cholesterol, dietary fiber, and other nutrientsof health concern.

2) Theylist % Daily Values. These % values help us see how a food fits into ouroverall daily diet.

3) Food Labels have consistent serving size amounts tomake it easier to compare similar foods.

Front 67

Describe Famine:

Back 67

Are large-scale food shortages, with widespread starvation, socialdisruption, and economic chaos.

Front 68

Define Malnourishment:

Back 68

Is a general term for nutritional imbalances caused by a lack ofspecific nutrients.

Front 69

Define Obese:

Back 69

Generally considered to mean more than 20% overthe ideal weight for a person’s heightand sex.

Front 70

In class, evidence was provided that revealed (given an identicalcalorie intake) a person would be 10% heavier today than 30 years ago. In other words, to lose weight today, you haveto eat less and exercise more than 30 years ago. Please identify the factors presented inclass suspected to contribute to this recent finding.

Back 70

1) Constant exposure to low levels of environmental chemicals found in many foods and personal-careproducts.

2) Exposure to such environmentaltoxins in the womb is also believed to program the body’s “set point” forgaining weight later in life.

3) Increased use of prescriptiondrugs listing weight gain as a side effect.

Front 71

According to the Center for Disease Control,(CDC) there are three major reasons that antibiotics are routinely fed to livestock and poultry. Please identify these three reasons.

Back 71

1) Treat sick animals.

2) Prevent disease among animals susceptible to infections.

3) Promotethe growth of cattle, poultry and swine.

Front 72

Inclass, there were three environmental concerns about the efficient productionof livestock in confined animal feeding operations (CAFO). Please identify these three concerns.

Back 72

1) Land conversion from pasture to soy andcorn fields raises the rate of soil erosion.

2) Bacteria in the manure or liquid wastesin storage lagoons (holding tanks) can escape into the natural environment.

3) Use of steroids andantibiotics in livestock feed to promote growth.

Front 73

Toxicology is the study of toxins and theireffects (particularly on living systems). Please identify the four areas of concern that “Environmental Toxicology”deals with.

Back 73

1) Interactions of toxic chemicalsin the environment

2) Transformation of chemicals inthe environment that produces toxic substances.

3) Fate,Effectsof natural and synthetic chemicals in the biosphere.

Front 74

Evolutionary theory predicted that bacterial resistance to antibiotics would happen, and it is evolutionary theory that gives us specific strategies for delaying this evolution of antibiotic resistance. Identify the 4 strategies presented in class that can delay this antibiotic resistance.

Back 74

1) Don’t use antibiotics to treat viruses.

2) Avoid mild doses of antibiotics over long periods of time.

3) When treating a bacterial infection with antibiotics, take all yourpills.Usea combination of drugs to treat bacterial infection.

Front 75

As presented in class, pleaseexplain what an “emergent disease” is, and provide two examples presented inclass.

Back 75

Emergent diseases are those not previously known, or that have been absent for at least 20 years.

Examples: 1) The H1N1 (new strain of bird flu) – 2009. 2) Mad Cow Disease – 1997 3) SARS – 2003 4) West Nile Virus – 2003

Front 76

Please explain LD50?

Back 76

LD50 is a convenient way to describe toxicity of a chemical by determining the dose to which 50% of the test population is sensitive. LD stands for lethal dose.

Front 77

Define Bioaccumulation:

Back 77

Is the selective absorption and storage of a great variety of molecules in cells such as essential nutrients and minerals, but can result in storage of harmful substances as well.

Front 78

Define Biomagnification:

Back 78

Is when the toxic burden of a large number oforganisms at a lower trophic level is accumulated and concentrated by apredator in a higher trophic level.

Front 79

Please identify and explain the two ways thatmicrobes acquire antibiotic resistance.

Back 79

(a) Random mutations: Make a few cells resistant. Whenchallenged by antibiotics, only those cells survive to give rise to a resistantcolony.

(b)Sexual reproduction (conjugation)or plasmid transfer moves genes from one strain or species to another.

Front 80

As presented in class, name and describe the twolowest layers of the atmosphere.

Back 80

a. Troposphere: The layer immediately adjacent to the earth’s surface. Within the troposphere, air circulates vertically and horizontally. Weather occurs here.

b. Stratosphere: The stratosphere extends about 50 km (31 mi) out from the tropopause. It is far more dilute than the troposphere, but has a similar composition except it has almost no water vapor and nearly 1,000 times more ozone. Unlike the troposphere, the stratosphere is relatively calm, with little mixing in the stratosphere.

Front 81

As presented in class, explain the “greenhouseeffect”, and explain how it relates to the theory of global climate change.

Back 81

The greenhouse effect is a common term to describe the capture of energy by gases in the atmosphere. It defines how atmospheric gasses such as CO2 and methane capture energy, and maintains atmospheric temperatures.

The greenhouse effect relates to the theory of Global Climate Change by explaining how burning of fossil fuels increases atmospheric gasses such as CO2, that affects this energy capture, resulting in a theoretical increase in atmospheric temperature that could affect world climate.

Front 82

Climate control is considered a classicfree-rider problem. As presentedin class, please explain what a “free-rider” problem is, then identify the most significant question that needs to be addressed relative to the“free-rider” problem, and the issue of climate control.

Back 82

Thefree-rider problem is an issue where nobody wants to take action for fear thatsomeone else might benefit from their sacrifices.Inclimate control, the principle question related to the free-rider problem iswhether the sacrifices need necessarily be as big as some policy makerssuggest.

Front 83

What is the Kyoto Protocol, and what are the most significant differences between the Kyoto Protocol and the Montreal Protocol?

Back 83

In Kyoto, Japan, in 1997, 160 nations agreed to roll back CO2, methane, and nitrous oxide emissions about 5 percent below 1990 levels by 2012, but China and India were exempted from the agreement and the U.S. never ratified this agreement. The differences between the Kyoto and Montreal Protocols are:

a. The Montreal Protocol addressed ozone depleting chemicals, while the Kyoto Protocol attempted to address greenhouse gas production, and the associated theory of Climate Change.

b. The Montreal Protocol actually worked, and the Kyoto Protocol failed.

Front 84

In 1970, the Clean Air Act designated new airquality standards to be applied equally across the country for six majorpollutants. Please identify the termused for these pollutants, and identify these six major pollutants.

Back 84

The six major pollutants are referred to as conventional or criteriapollutants, and they include:

1) sulfur dioxide

2) nitrogen oxides

3) carbon monoxide

4) ozone (and its precursor volatile organic compounds)

5)lead

6) Particulate matter.

Front 85

Please explain what a Hazardous Air Pollutant(HAPs) is as defined by the U.S. EPA.

Back 85

HAPs are a special category of toxins that are monitored by the U.S. EPA because they are particularly dangerous. These chemicals cause cancer, nerve damage, disrupt hormone function, and fetal development. These persistent substances remain in ecosystems for long periods of time, and accumulate in animal and human tissues.

Front 86

Define primary and secondary airpollutants.

Back 86

a) PrimaryAir Pollutants: Primary pollutants are releasedin a harmful form.

Secondary pollutants: Only become hazardous after reactions in the air.

Front 87

Define point source and fugitive or nonpoint-source as they relate to the Clean Air Act.

Back 87

Pointsource: Is a smokestack or some otherconcentrated pollution origin. It is themost regulated source of pollution.

Fugitive orNonpoint-source: Are emissions that do not have a specific point oforigin, such as a smokestack. Thesepollutants are normally not regulated.

Front 88

In 1986, Congress established the Toxic ReleaseInventory (TRI). As presented in class, please explain the TRI.

Back 88

The TRI is designed to help inform communities abouttoxic substances produced and handled in their area. This inventory collects self-reportedstatistics from 23,000 factories, refineries, hard rock mines, power plants,and chemical manufacturers.

Front 89

Whatis an atmospheric inversion (or temperature inversion) and how does ittrap air pollutants?

Back 89

Atemperature inversion is a reversal of the normal behavior of temperature inthe lower atmosphere, in which a layer of cool air at thesurface is overlain by a layer of warmer air. (Under normal conditions airtemperature normally cools with height.)

Inversions play an important role in capturingpollutants at the Earth’s surface, as it acts as a cap on the upward movementof air from the layers below. Diffusionof dust, smoke, and other air pollutants is restricted by this cap, trappingthem at ground level.-fody

Front 90

Brieflyexplain the Capture/Mark/Recapture method for estimating species populations.

Back 90

A group of animals is captured, tagged, and thenreleased. You then capture another groupof the same kind of animals and see how many of them were previously capturedand tagged. By knowing how manyyou caught the first and second time, and how many were caught twice, you can“estimate” how many animals there actually are in the population.

Front 91

Capture/Mark/Recaptureis a method that estimates species populations. List 4 environmental factors which could affect a species population intheir natural habitat.

Back 91

1) Species birth rate

2) Immigration/Emigration

3) Food supply

4) Death Rate(disease/predation)

5) Habitat (gain or loss)

Front 92

Identify three problems with the Capture/Mark/Recapture technique for estimating population size that couldaffect its accuracy?

Back 92

1) Capturing, marking handling can be very stressful to animals.

2) Not suitable for animals that migrate, or are highly transient.

3) Requires a high percentage of the population to be captured and marked

4) Some animals may become 'trap-shy' and avoid the traps after the first capture, while some animals may become 'trap-happy', particularly if the traps are baited.

5) Marks may make individual animals more, or less attractive to predators than non-marked individuals.

6) The method assumes equal catchability of all animals, but “catchability” of animals may vary with different life stages, seasons, times of day etc.

Front 93

Please identify 4 soil characteristics that the size of soil particlesdistinctly affects.

Back 93

1) Water holding capacity

2) Aeration

3) Runoff

4) Compaction

5) Erodibility

Front 94

Soil particle size are related to soil pore size and number that is critical with affecting how soil functions. Please identify the two principal sizes of soil pores presented in class, and describe how these two sizes affect soil function:

Back 94

The two soil pore sizes are:

1) Macropores (aeration pores) – these are the larger pores that affect soil function by creating the easiest pathways for air and water that largely determine the movement of air and water through the soil.

2) Micropores – are the small pores that affects soil function by retaining some water for plant use, as it drains down through the soil.

Front 95

In class, it was identified that soil particle size affects two soil features. Please identify what these two soil features are, and briefly explain how each:

Back 95

1) Specific Surface Area: Determines how soil retains water and nutrients, making them available for plant use.

2) Soil Pores (number and size): Determines how air and water move and are retained in the soil for plant use.

Front 96

You have collecteddata to determine the LD50 of a population. After subjecting an initial population of______ animals to a known toxin, you have _______ survivors. Based on this data, please calculate thepercent mortality.

Back 96

Example: You have an initial population of 10 animalsand have 6 survivors after exposing them to a known toxin. The % mortality iscalculated as = I ‐ S x100 or 10– 6 x 100 = 40%. Where I = Initial population, and S = Survivors.