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Genetic Diversity: encompasses the differences in DNA composition among individuals within species3. Ecosystem diversity: the number and variety of ecosystems
What are the five primary reasons of biodiversity loss?
1. Habitat alteration: greatest cause of biodiversity loss, caused by almost human activity2. Invasive species: Our introduction of non-native species to a new environment3. Pollution4.
Climate change: This is the only one that has global impact. 5. Overharvesting: when people hunt or harvest an organism too much (i.e. Siberian tiger)
List five invasive species, and describe their impacts.
1. Gypsy moth: it defoliates trees over large regions every few years. 2.
European starling: brought by Shakespeare devotees who wanted to bring all birds from his plays to America. They are thought to outcompete native birds for nesting holes. 3. Cheat grass: crowds out other grass, depletes nitrogen, burns readily4. Brown tree snake: caused extinction of almost all native forest bird species in Guam.
5. Asian long-horned beetle: burrow into trees and interfere with trees ability to process water and nutrients
Define ecosystem services. Give three examples that most people would have a hard time replacing.
Ecosystem services are valuable processes that are provided by intact ecosystems.
1. Provides food, fuel, and fiber.2. Provides shelter and building material.3. Stabilizes and moderates Earth’s climate.
What is the relationship between biodiversity and food security? Between biodiversity and pharmaceuticals? Give three examples of potential benefits of biodiversity in food and medicine.
Biodiversity benefits agriculture. 1. babassu plant produces mor vegetable oil than any other plant.2. seredipity berry prouces a sweetner 3,000 times sweeter than sugar.3. several species of salt-tolerant grasses and trees are so hardy that farmers can irrigate them with saltwater.
Organisms provide drugs and medicines1. rosy periwinkle produces compounds that treat Hodgkin’s disease.2. a rare species of cork in Australia provides a compound used to cure stomach cancer.3. Another Australian plant can treat lymphoid leukemia.
Describe four reasons why people suggest biodiversity conservation is important.
1. Because biodiversity enhances food security2. oraganisms provide drugs and medicines3. biodiveristy helps ecosystems function4. people value connections with nature.
What is the key difference between an umbrella species and a keystone species? Could one species be both?
A keystone species is a species whose existance dictates the survival of a whole ecosystem.
An umbrella species is a species that requires a large area of habitat. Conservationists use these species to protect less charismatic species like fungi.Yes, a species could potentially be both.
Explain the theory of island biogeography.
The theory explains how the number of species on an island results from an equilibrium balance between the number added by immigration and the number lost through extirpation. It predicts and island’s species richness based on island’s size and distance from the island.
1. Distance effect: more species colonize to the islands close to mainland.2. More species colonize to larger islands,3. Differential extinction: proportionately fewer xpecies go extinct on larger islands.
Name two successful accomplishments of the U.S. Endangered SPecies Act. Name two reasons some people have criticized it.
Birds such as the bald eagle, the brown pelican and other birds of prey have recovered and are no longer endangered,The red-cockaded woodpecker jave jeld formerly declining populations steady in face of continued pressure.
What is a biodiveristy hotspot? Describe community-based conservation.
A hotspot is an area that supports an especially great number of species that are endemic to the area. Community- based conservation is an approach that engages local people in efforts to protect land and wildlife.
What four major types of health hazards does research in the field of environmental health encompass?
Physiscal: landslides, hurricanes, fires, sunburns etc. Chemical: synthetic chemicals such as disinfectants or pesticidesBiological: infectious disease, mosquitoes.
Cultural: smoking, unsafe workplace
In whayt way is disease the greatest hazard humans face? What kinds of interrelationships must environmental health experts study to learn about how diseases affect human health?
It accounts for a quarter of deaths worlwide and despite technological advances, we are still battling it. Scientists need to learn about relationships between humans and disease vectors. Also they have to understand how climate change and habitat alteration will affect the spread of disease.
Where does most exposure to lead, asbestos, radon, and PBDEs occur? How has each one been addressed?
The exposure to these things occurs indoors. Lead: Paint and pipes are no longer made out of lead.Radon: Radon testing on homes is encouraged to prevent lung cancer.
Asbestos: It has been removed from schools and offices, although the dangers of exposure from asbestos removal may exceed the dangers of leaving it.PBDE: the European union banned them, but the US has done little to address issue
When did concern ver the effects of pesticides start? Describe the arguments in Silent Spring? What policy resulted from the book? Is DDT still used?
The awareness of pesticides began with the publication of Silent Spring. DDT is hazardous to people’s health. The use of DDT was was banned in the United States
List and describe the six types or general categories of toxicants described.
Carcinogens: chemicals that cause cancerMutagens: chemicals that cause mutations in the DNAteratogens: affect the development of human embryos in the womb.
neurotoxins: chemicals that attack the nervous system.allergens: overactivate the immune system.
How do toxicants travel through the environment and where are they most likely to be found? What are the life spans of toxic agents?
Some travel through water, and concentrate in small amounts of ground water. Others travel through the air. Toxicants can degrade quickly or persist for decades.
What are epidemiological studies, and how are they most often conducted?
Epidemiological studies are large-scale comparisons among groups of people, usually contrasting a group exposed to some hazard with an unexposed group.
Why are animals used in laboratory experiements in toxicology? Why is a substance with a high LD50 considered safer than one with a low LD50?
Animals are used because it would be unethical to use humans.A high LD50 means that he lethal dose for 50% of the population is high.
A low LD50 indicates high toxicity.
What factors may affect an individuals response to a toxic substance? Why is chronic exposure difficult to detect?
The difference in individual’s reaction to toxicants can be genetically based or due to a person’s current condition. It can also vary due to sex, age, and weight. Because of the long time period involved, the cause and effect relationship of chronic exposure may not be readily apparant.
How do scientists identifu and assess risks from substances or activities that may pose health risks?
Through risk assessment. First scientist determine whether a given substance has toxic affects. Then they assess the populations likely extent and length of exposure.
Compare and contrast the main types of freshwater ecosystems.
River and streams: water from rain, snowmelt, or springs runs downhill and converges where the land dips lowest.Lakes and ponds: bodies of open standing water.Marshes, swamps, and bogs: systems that contain elements of fresh water and dry land.
Name and describe the zones of a lake.
Littoral zones: area around the nutrient-rich edeges of water. Water is shallow enough for plants to grow in mud and reach above water. Benthic zone: extends along the bottom of the lake or pond, from shore to the deepes point.Limnetic zone: In the open part of lake, the limnetic zone is the shallow part that sunlight penetrates.Profundal zone: below limnetic zone, in open lake, where sun does not penetrate.
Describe three benefits of damming rivers, and three costs. What environmental, health, and social concerns has China’s Three Gorges Dam raised?
Benefits: prevent floods, provide drinking water, produce electricity.Costs: very expensive, can cause flooding of certain areas, slows water flow which lets sediment settle. China Dam:Environmental: It is submerging farmland and wildlife habitat. Health: It allows suspended sediment settle in the reservoir. Social: over 1.13 million people have been displaced, and a 10,000 year old archaeological site has been submerged
Name three types of freshwater pollutants, and provide an example of each. What ecological effects do each of these produce? List three properties of water that scientists use to determine water quality.
Three types:1. Nutrient pollution: caused by runoff of fertilizers from farms, lawns, and golf courses. This causes eutrophication and hypoxia.2. Toxic chemicals: comes from pesticides, petroleum products, and other sythetic chemicals. Poison animals, cause health problems in humans.
3. Thermal pollution: caused by using water from river to cool an industrial facility. Kills firsh, and decreases amount of oxygen. Water quality indicators: 1.
Biological: presence of fecal coliform bacteria2. Chemical: pH,taste and odor, and hardness.3.Physical: temperature, color, and turbidity.
Why do many scientist consider groundwater pollution a greater problem than surface water pollution?
It is hidden from view and difficult to monitor; it is also more difficult to manage.
Explain the steps in wastewater treatment.
How does artificial wetlands aid in such treatment
The primary treatment removes the contaminants in tanks. It removes 60% of solids. In secondary treatments, water is stirred and aerated so aerobic bacteria degrade organic pollutants. Then water is treated with chlorine. Wetlands cleanse water. Microbes decompose pollutants.
What proportion of Earth’s surface do oceans cover? What is the average salinity of ocean water? What factors drive the system of ocean current?
Oceans cover 71% of our planet’s surface. Ocean water is 3.
5% salt.Wind, solar heating and cooling, gravity, density differences, and the Coriolis effect drive the ocean currents
Describe three kinds of ecosystems found near coastal areas and the kinds of life they support. How are these systems being affected by human impact?
Ecosystems: 1) Near-surface pelagic ecosystems: photosynthetic activity is concentrated near the surface .2)Deep ocean: animals have adapted to deal with extreme water pressures and to live in the dark.3) Kelp forests: they provide shelter and food for fish which provide food for sharks.
They are suffering from pollution, habitat alteration, and overfishing.
Describe three major forms of pollution in the oceans and the consequences of each.
Nets and plastic debris: Marine animals die from ingesting it or nets may snare animals.
Oil pollution: It coats and kills animals, and poisons them when they ingest it. Excess nutrients: create dead zones; and cause population explosions.
Name three industrial fishing practices that create by-catch and harm marine life, and explain how they do so.
Longline fishing: involves setting out extremely long lines with up to several thousand baited hooks spaced along their lengths. Trawling: entails dragging immense cone-shaped netes through the water with weights at the bottom nad floats at top to keep nets openDriftnetting: nets that span large expanses of water, arrayed to strategically drift with current a capture passing fish.
How does a marine protected area differ from a marine reserve?
Marine Protected areas allow fishing, and marine reserves do not.
Why are fossil fuels our most prevalent source of energy today? Why are they considered nonrenewable sources? How are they formed?
It is the the most convenient and efficient. They are non renewable because they are in limited supply and we will use the reserves in the coming decades. They are formed from the remains from organisms from past geological ages.
Describe how net energy differs from energy returned on investment. Why are these concepts important when evaluating energy sources?
Net eregy= energy returned – energy investedEROI = Energy returned / energy investedIt helps us determine the cost of harnassing energy and how much energy we receive.
Describe how coal is used to generate electricity.
In plants, coal combustion converts water to steam, which turns a turbine to create electricity .
How do we create petroleum-based products?
Oil refineries sort the various hydrocarbons of crude oil, spearating those intended for use in gasoline engines from those, such as tar and asphalt, used for other purposes.
Explain why many scientists and oil experts are prediction that global oil production will soon decline.
Hubbert was able to calculate that U.S. oil production would decline in 1970. He was correct and now scientists have calucaltied global production with decline in the next decade.
Describe at least two major impacts of fossil fuel emissions. Describe at least one major impact of fossil fuel reliance for national economies or government.
Fossil fuel emissions pollute air and drive climate changeFossil fuel use pollutes water and alters environment
Describe two main approach to energy conservation and give an example of each.
1. Personal choice: driving less, turning off lights2. Increases efficiency: increase fuel efficiency in cars, cogeneration