week 10 . questions

Which of the following is directly responsible for depleting the supply of oxygen in bottom waters? Question 3 choices Choice A., bacterial growth Choice B., algal growth Choice C., expanding fish and invertebrate populations

Choice A., bacterial growth

Which of the following actual (i.e., real) products of biological activity is not likely to be a source of the increases in greenhouse gases observed in recent history? Question 4 choices Choice A., carbon dioxide produced as a result of aerobic cellular respiration in living organisms Choice B., carbon dioxide produced by use of fossil fuels in automobiles, heating and cooling, and industry Choice C., increases in the amount of water vapor the atmosphere can hold (or relative humidity) at higher global temperatures

Choice A., carbon dioxide produced as a result of aerobic cellular respiration in living organisms

Nitrogen fertilizer is added to farmland to improve crop yield and quality. While farmers are working to reduce the amount of runoff from fields, some of the fertilizer enters streams. The streams flow into the Mississippi River and ultimately into the Gulf of Mexico where the added nitrogen supports increased algal and cyanobacterial blooms. The addition of nutrients to water systems, which causes increased growth of algae and cyanobacteria, is termed: Question 4 choices Choice A., nitrification. Choice B., eutrophication. Choice C., quantification. Choice D., fertilization.

Choice B., eutrophication.

Which of the following is reflected back to the Earth's surface by greenhouse gases? Question 1 choices Choice A., solar radiation Choice B., infrared radiation Choice C., visible light Choice D., carbon dioxide

Choice B., infrared radiation

What is the source of the elevated nutrients in the water that cause the formation of dead zones in the Gulf of Mexico? Question 2 choices Choice A., increased fertilization of the water by the waste generated by expanding fish populations Choice B., industrial pollution in Southeastern states through which the Mississippi River flows. Choice C., agricultural runoff from much of the central United States

Choice C., agricultural runoff from much of the central United States

Which of the following is responsible for the increased growth of algae in the dead zones? Question 1 choices Choice A., elevated carbon and nitrogen in the water Choice B., elevated carbon and phosphorous in the water Choice C., elevated nitrogen and oxygen in the water Choice D., elevated phosphorous and nitrogen in the water Choice E., elevated phosphorous and oxygen in the water

Choice D., elevated phosphorous and nitrogen in the water

Which of the following is not an example of a greenhouse gas? Question 2 choices Choice A., carbon dioxide Choice B., methane Choice C., water vapor Choice D., oxygen

Choice D., oxygen

Which of the following is false concerning the development of dead zones in coastal waters, for example, the dead zone in the Gulf of Mexico? Question 5 choices Choice A., Higher levels of nutrients entering streams and ultimately the oceans lead to overproduction of algae and cyanobacteria. Choice B., When alive, the algae and cyanobacteria photosynthesize and produce oxygen but only during the daylight hours. Choice C., High concentrations of algae and cyanobacteria require oxygen to survive during the dark hours of the day, leading to depletion of oxygen levels. Choice D., When they die, algae and cyanobacteria sink to the bottom of the coastal zones where heterotrophic aerobic bacteria feed on them and deplete the water of oxygen. Choice E., Dead zones in coastal waters of the oceans have been a common occurrence for many thousands of years.

Choice E., Dead zones in coastal waters of the oceans have been a common occurrence for many thousands of years.

Which of the following is false? Question 3 choices Choice A., Light energy from the sun warms the surface of the Earth's continents and the ocean. Choice B., Approximately 50% of the sun's light energy does not reach the surface of the Earth. Choice C., The Earth radiates heat energy back to the atmosphere. Choice D., Much of the heat that is lost from the Earth's surfaces is re-radiated back into the atmosphere by greenhouse gases. Choice E., The greenhouse gases in the atmosphere have all come from human activity

Choice E., The greenhouse gases in the atmosphere have all come from human activity

4. Nutrients from croplands are carried by the Mississippi River into the Gulf of Mexico. If nutrients are good for growth, why are scientists concerned about this nutrient influx? Higher productivity may support greater diversity of phytoplankton species. Higher productivity may support greater numbers of sharks. Higher productivity may result in increased respiration on sinking algal material, depleting oxygen within gulf waters. The nutrient runoff depletes nitrate, which cannot be made industrially.

Higher productivity may result in increased respiration on sinking algal material, depleting oxygen within gulf waters.

4. Which of the following statements is TRUE regarding the process of eutrophication? It can result in "dead zones" devoid of aquatic animal life. All of these choices are correct. It is the result of the natural accumulation of nitrogen in bodies of water. It increases the oxygen content of water by promoting bacterial growth. It increases the species diversity and health of bodies of water.

It can result in "dead zones" devoid of aquatic animal life.

9. In the example of the giant kelp forests on the Pacific coast, a rise in the otter population would have what effect on the kelp populations? Kelp populations would increase due to an increase in sea urchins. Kelp populations would increase due to a decrease in sea urchins. Kelp populations would be totally unaffected by the otter population. Kelp populations would decrease due to increased predation by otters. Kelp populations would decrease due to an increase in sea urchins.

Kelp populations would increase due to a decrease in sea urchins.

5. What is generally true about biomass and energy as we move from one trophic level to the next? Organisms at one trophic level always consume all of the resources from the level below them. Biomass increases but energy decreases. All of the energy stored initially in organic molecules by the primary producers will be available to the secondary consumers. They both increase. Not all energy is transferred to the next trophic level.

Not all energy is transferred to the next trophic level.

7. So-called "dead zones" in coastal oceans are associated with nutrient runoff and oxygen-depleted bottom waters. What causes the oxygen depletion? Nutrient runoff causes population growth of cyanobacteria and algae which, in turn, support the growth of fish populations. Fish consume oxygen via aerobic respiration. Nutrient runoff causes population growth of algae, which consume oxygen via aerobic respiration. Nutrient runoff causes population growth of cyanobacteria and algae, which consume oxygen via aerobic respiration. Nutrient runoff causes the waters to warm, which causes them to lose oxygen. Nutrient runoff causes algae and cyanobacteria populations to grow. When they die, they are consumed by heterotrophic bacteria that consume oxygen via aerobic respiration.

Nutrient runoff causes algae and cyanobacteria populations to grow. When they die, they are consumed by heterotrophic bacteria that consume oxygen via aerobic respiration.

2. Which of the following statements explains how an oxygen-rich atmosphere was possible? Rates of oxygen consumption were lower than rates of photosynthesis. Photosynthetic organisms have existed on earth longer than heterotrophs. The number of plants has always outnumbered the animals. All of these choices are correct. Rates of carbon fixation and respiration have always been equal.

Rates of oxygen consumption were lower than rates of photosynthesis.

4. If Earth had no oceans, would temperatures at the equator be hotter or colder than they are now? This question can't be answered without additional information. Temperatures would be colder. Temperatures would be hotter. Temperatures would remain the same.

Temperatures would be hotter.

4. A group of scientists in Alaska notices that not only have atmospheric CO2 levels increased at their sampling site but so too have methane levels. What most likely accounts for this increase in methane levels? The melting of permafrost accompanied by the thawing of methane-producing bacteria. A decrease in beef production near the researchers' sampling area. The failure of rice paddies to be established in Alaska, given its climate. None of the answer options is correct. The release of methane from thawed permafrost.

The release of methane from thawed permafrost.

3. Biologists who study biodiversity describe new species and monitor species of which we are aware. Why is the study of biodiversity important in the Anthropocene? The study of biodiversity is important because it provides information about the number of species that go extinct every 1000 years. The study of biodiversity is important because many politicians are biologists and they can influence government policy. The study of biodiversity is important because if we don't count all the species on the planet, then we won't be able to identify more potential sources of food. The study of biodiversity is important because it helps quantify the effects of human actions on changes in the traits of many populations (size, density, distribution).

The study of biodiversity is important because it helps quantify the effects of human actions on changes in the traits of many populations (size, density, distribution).

4. While food chains show linear energy transfer between organisms, food webs depict more realistically what occurs in an ecosystem. False True

True

5. The evolution of biodiversity on the planet can be linked to patterns in the carbon cycle over time. False True

True

6. If all other aspects of their lifestyles were equivalent, a vegetarian would have a smaller ecological footprint than someone who consumes a large amount of meat. False True

True

Increased overfishing on predators of crown-of-thorns starfish is likely to result in continued increase in crown-of-thorns starfish population sizes. True False

True

Some forms of M. tuberculosis are very difficult—or even impossible—to treat with antibiotics. True False

True

5. In terrestrial ecosystems, nitrogen is returned to the atmosphere by: All of these choices are correct. denitrifying bacteria. nitrifying bacteria. nitrogen-fixing bacteria.

denitrifying bacteria.

3. Which of these biomes receives the least amount of rainfall, and therefore has low primary production, nutrient-poor soil, and plant species that are adapted for water-storage? savannah desert tundra chaparral alpine

desert

5. In deeper waters, nutrients primarily come from: thermal vents. surface winds creating deep ocean currents. glacial ice melt. detritus from more productive shallower waters.

detritus from more productive shallower waters.

3. Increased phosphate levels in the Everglades has led to: increased plant growth and diversity. displacement of native plants by phosphate-loving introduced plants. expansion of native plants into adjacent ecosystems. eutrophication followed by declines in fish and alligator populations. declining populations of low-phosphate adapted cattails.

displacement of native plants by phosphate-loving introduced plants.

. You decide to plant a garden in your backyard. You dig up a strip of grass in a sunny spot. When you have finished digging up the grass, but you haven't planted anything, you have created a(an) _____ in the lawn. ecological disturbance and a new community new community ecological disturbance None of the answer options is correct.

ecological disturbance

4. Keystone species can have significant influences over several populations in a community through their: avoidance of antagonistic interactions. ability to leave their environment relatively unchanged. large body sizes. effect on high amounts of biomass and energy transfer between populations. roles as prey species for predator populations in the community.

effect on high amounts of biomass and energy transfer between populations.

2. In marine ecosystems phosphorus is added to the ecosystem primarily from: dead organisms that fall to the bottom of the ocean. glacial ice melt. erosion of rocks on land. fixation of atmospheric phosphorus.

erosion of rocks on land.

Nitrogen runoff leads to large increases in the populations of algae and cyanobacteria in lakes and oceans in a process known as: eutrophication. global warming. ocean acidification. the greenhouse effect.

eutrophication.

6. In which of the following regions would you expect to find river biomes with HIGH levels of oxygen in the water? slow-moving, clear-water rivers in the Rockies fast-moving, muddy rivers in the Amazon fast-moving, clear-water rivers in the Rockies slow-moving, muddy rivers in the Amazon

fast-moving, clear-water rivers in the Rockies

3. A _____ depicts the flow of carbon through an ecosystem, whereas a _____ depicts the transfer of energy. food web; trophic pyramid niche; food web food web; niche trophic pyramid, food web

food web; trophic pyramid

4. Genetic variation within species is important to conservation because: species with low genetic variation go extinct. high levels of genetic variation will result in more populations' speciating, so biodiversity will be maintained. low levels of genetic variation may make hybrid species more likely, so neither species will go extinct. genetic variation provides material for natural selection to "act upon" in changing environments.

genetic variation provides material for natural selection to "act upon" in changing environments.

2. Warm air is _____ dense than cold air, and warm air holds _____ moisture than cold air. less; more less; less more; more more; less

less; more

Given models of population growth, which model would be the BEST to use for determining estimated sustainable yield? logistic exponential a combination of both

logistic

4. Decomposers are vital components of a food web because they: return carbon (as CO2) to the atmosphere. immediately provide tertiary consumers with usable forms of carbon. serve as primary producers. incorporate the carbon contained in atmospheric CO2 into C6H12O6.

return carbon (as CO2) to the atmosphere.

3. Most climate models predict that, during the 21st century, mean global temperature will increase by: 1-3°C. 5-7°C. 2-5°C. 7-10°C. 12-15°C.

2-5°C.

How many "cells" of circulating air are found around the Earth? 12 6 3 9

6

2. What is the approximate size of the human population today? 25 billion people 7 billion people 5 billion people 2 billion people 10 billion people

7 billion people

6. Which of the following factors likely contributed to the accumulation of O2 within Earth's atmosphere? the fact that oxygen is also cycled during the carbon cycle the fact that there is a slight "de-coupling" between photosynthesis and respiration the fact that photosynthesis releases O2 as a product All of these choices are correct. the evolution of cyanobacteria

All of these choices are correct.

7. Which of the following statements about coral bleaching is TRUE? Coral bleaching results from the loss of algal symbionts from the coral tissue. Corals appear white after bleaching because their white calcium carbonate skeletons are visible through their translucent tissue. All of these choices are correct. Bleached corals die more rapidly than unbleached corals. Increased seawater temperature is one cause of coral bleaching.

All of these choices are correct.

In general, what is the relationship between a country's ecological footprint and its overall standard of living? None of the answer options is correct. As the standard of living decreases, the ecological footprint increases. It depends on country—in developed countries, the ecological footprint and standard of living are positively correlated; in developing countries, they are negatively correlated. It depends on the country—in developing countries, the ecological footprint and standard of living are positively correlated; in developed countries, they are negatively correlated. As the standard of living increases, so does the ecological footprint. .

As the standard of living increases, so does the ecological footprint.

3. If all of the tertiary consumers were removed from an environment, the associated food web (and thus the carbon cycle) would collapse. True False

False

3. Most of Earth's primary production comes from tropical rainforests. False True

False

5. Predator/prey relationships are always linear, with one species affecting only one other in the community. False True

False

6. The sequence of species that colonize a recently disturbed area through succession is unpredictable. True False

False

7. Why are microorganisms like fungi, bacteria, and archaeons so important to the carbon cycle? These microorganisms bridge the carbon cycle between terrestrial and marine environments. Many of these microorganisms generate carbon dioxide, making it available for primary producers. These microorganisms form their own portion of the carbon cycle in case other areas of the carbon cycle fail. These microorganisms generate the oxygen necessary for aerobic organisms.

Many of these microorganisms generate carbon dioxide, making it available for primary producers.

8. Which of the following statements reflects an evolutionary change that is in line with the Red Queen hypothesis? a species of beetle that goes extinct when farmers start spraying insecticide a species of beetle that has two new mutations that confer resistance to an insecticide a species of beetle that switches to production of offspring solely through parthenogenesis a species of beetle that begins to hybridize with another species of beetle in its habitat

a species of beetle that has two new mutations that confer resistance to an insecticide

3. An individual's ecological footprint is equivalent to the: total amount of carbon emissions from that individual's car. total amount of food consumed by that individual. amount of land required to provide all the resources used by that individual. All of these choices are correct. total amount of energy used by that individual

amount of land required to provide all the resources used by that individual.

6. If a scientist wanted to determine if a forest environment had been polluted, which of the following groups of organisms typically would be the BEST indicator for the presence of pollutants? fish amphibians insects mammals birds

amphibians

On land, _____, which are broad, ecologically uniform areas, are recognized by their characteristic vegetation that reflects adaptation of form and physiology to climate. biomes countries continents latitudes

biomes

Autotrophs remove _____ from the air and fix this into tissues providing _____ for secondary consumers. nitrogen; energy nitrogen; amino acids carbon dioxide; inorganic molecules carbon dioxide; energy

carbon dioxide; energy

5. In addition to burning fossil fuels, humans return CO2 to the atmosphere faster than it can be removed by: polluting the oceans. clearing forests for agriculture. generating nutrient pollution. expanding rice production.

clearing forests for agriculture.

10. The sum total of the populations that live in a given area is called a(n): ecosystem. community. habitat. interaction.

community.

2. Sustainable development plans are designed to allow: conservation of species used by humans so that decreases in population size can be easily monitored and reversed. conservation of species used by humans without causing the decline or extinction of that species. conservation of species that are only found in the oceans because population sizes are easier to maintain in marine species. conservation of species that are only found in regions of high human population because those are most likely to decline in population through human use.

conservation of species used by humans without causing the decline or extinction of that species.

3. The high specific heat of water means that land masses near the equator are: warmer than predicted because of all the heat in the water being released into the air. the same temperature regardless of the presence of water because it is only the amount of solar radiation on the land mass that affects temperature. cooler than predicted because of all the heat carried by ocean waters from low to high latitudes.

cooler than predicted because of all the heat carried by ocean waters from low to high latitudes.

4. Moderate temperatures and precipitation, as well as nutrient-rich soil due to annual leaf fall, characterize this biome. taiga deciduous forest temperate grassland temperate coniferous forest savannah

deciduous forest

7. Which group in a food web is responsible for returning inorganic compounds back to the environment? secondary consumers primary producers tertiary consumers decomposers primary consumers

decomposers

8. A(n) _____ is a community of organisms and the physical environment it occupies. metapopulation population community interaction ecosystem

ecosystem

2. A dead zone has been documented off the coast of Oregon. Which of the following could contribute to the formation of the dead zone? high nitrogen levels in the area high carbon dioxide levels in the area high oxygen levels in the area high phosphate levels in the area =

high nitrogen levels in the area

6. Remember that, as a rule, temperatures decrease with an increase in altitude. If you were studying the effects of climate change on the geographic ranges of species living in the mountains and your climate records showed that mean temperatures were increasing, you would predict that species ranges would show a shift toward: higher elevations. None of the answer options is correct. intermediate elevations. unpredictable elevations—the precise response would depend on individual species, with no clear trends or averages. lower elevations.

higher elevations.

4. If phosphorus concentrations were to suddenly increase in a marine ecosystem, which of the following would likely occur? increased primary productivity decreased primary productivity no change in the rate of primary productivity

increased primary productivity

As a young field biologist, you are walking through a patch of grassland where you notice that there is a very common, well-established species of grass. Further research shows that this grass is native to an area in another part of the world. This species of grass would be classified as a(n) _____ species. invasive keystone native

invasive

2. A species that has a disproportionately large effect on a community is called a _____ species. linchpin engineer central keystone producer

keystone

8. Ultimately, the nitrogen cycle is dependent on: respiration rates of heterotrophs. nitrogenous waste production in different environments. addition of fertilizers to the soil. microorganisms that convert atmospheric N2 into usable forms.

microorganisms that convert atmospheric N2 into usable forms.

2. In either freshwater or marine biomes, which regions would you expect to have the HIGHEST productivity? just below the deepest level where sunlight penetrates in the middle depths of the biome at the deepest depth of the biome near the surface where sunlight penetrates

near the surface where sunlight penetrates

3. Which of the following is a good predictor of biodiversity in terrestrial ecosystems? plant species in a community predator species in a community pollinator species in a community prey species in a community

plant species in a community

3. Some biologists have suggested that overexploitation in the harvesting of some sharks (i.e. top predators) has caused drastic changes in marine communities. Which of the following would you expect after removal of a top predator from a community? population growth of prey species no change in marine communities population decline of prey species

population growth of prey species

Which of the following organisms can incorporate atmospheric carbon directly into C6H12O6, thereby playing a major role in a food web? grazers carnivores decomposers consumers primary producers

primary producers

6. The broadest level in a trophic pyramid is primarily composed of: secondary consumers. tertiary consumers. primary consumers. primary producers.

primary producers.

Organisms that take up inorganic nutrients and convert them to organic molecules such as carbohydrates and proteins are called: heterotrophs. predators. herbivores. consumers. primary producers.

primary producers.

5. Eutrophication describes the: total amount of nitrogen fertilizer that leaves agricultural fields as surface runoff. increased production of crops using fertilizer. death and decomposition of algal blooms. process in which added nutrient levels lead to the growth of algae and cyanobacteria populations, eventually causing oxygen availability to decline.

process in which added nutrient levels lead to the growth of algae and cyanobacteria populations, eventually causing oxygen availability to decline.

2. What is one "low-tech" method currently available to actively remove CO2 from the air? capturing CO2 in smokestacks (using smokestack scrubbers) expansion of rice farming reforestation of previously cleared landscapes None of the answer options is correct. using iron and other supplements to fertilize the ocean (increase phytoplankton biomass)

reforestation of previously cleared landscapes

7. Following a disturbance, the process by which species replace each other over time is/are called: keystone species. disturbances. ecosystem engineers. competition. succession.

succession.

5. Biological reserves are an important tool in maintaining biodiversity because a reserve: that is designed for a single species will also protect other species in the reserve. that is designed to protect the species there will always be maintained as a reserve. will generate income when people visit to see the biodiversity protected in the reserve. will not change over time so all the species will be conserved as long as the reserve exists.

that is designed for a single species will also protect other species in the reserve.

2. Energy flow through ecosystems can be depicted using a(n): trophic pyramid. food chain. ecosystem. food web. Calvin cycle.

trophic pyramid.

6. This biome is the coldest, with the lowest biodiversity and a permanent layer of ice beneath the soil. savanna temperate coniferous forest taiga alpine tundra

tundra

8. While biodiversity includes the number of species in a given area, it also includes: amount of primary productivity. unique phylogenetic lineages. abiotic factors that define the community. overall number of trophic levels in a food web.

unique phylogenetic lineages.