Unit 2

Question 1

The water cycle is an example of:

Answer 1

an ecosystem service

Question 2

Which ecosystem service is estimated to have the highest annual monetary value?

Answer 2

Nutrient recycling

Question 3

How can it be useful to place a monetary value on ecosystem services, even if we know it will not be accurate?

Answer 3

We are more likely to protect these vital services if we acknowledge that they do have value to us.

Question 4

The land needed to provide the resources for and assimilate the waste of a person or population is referred to as:

Answer 4

an ecological footprint

Question 5

Readily produced resources that can be used and still leave enough natural capital behind to replace what we took are known as:

Answer 5

natural interest

Question 6

The sap of maple trees (sap is “food” for the tree) can be tapped to make maple syrup, but taking too much will kill the tree. In this example, what would constitute the natural capital, and what would be the natural interest?

Answer 6

The natural capital would be the maple trees that produce the sap (was well as the resources they need to grow such as water, soil, nutrients, etc.). The natural interest would be the amount of sap that could be taken without compromising the tree’s ability to grow and produce sap the next year.

Question 7

True or False: Researchers use the IPAT model to estimate the size of an individual’s ecological footprint.

Answer 7

False

Question 8

What is the IPAT model? How is the equation I = P × A × T similar to and/or different from the equation I = (P × A)/T?

Answer 8

The IPAT model states that human impact on the environment (I) is a function of population size (P), affluence (A) and technology (T). As each of these increases, so too does human impact on the environment. But better technologies that improve efficiency and reduce resource use or pollution can actually reduce impact. In this case the equation becomes I = (P × A)/T.

Question 9

Which of the following is an internal cost of coal mining?

Answer 9

Wages paid to workers

Question 10

If we included external costs in the cost of a good or service, we would expect the price to:

Answer 10

go up as the users become responsible for paying all the costs.

Question 11

What is true cost accounting, and why would it be good for the environment if businesses internalized all external costs?

Answer 11

True costs accounting internalizes external costs when determining a fair price for a product or service in order to identify not only the financial investment made by a business but also the environmental and societal costs of doing business. When a good or service is priced at its true cost, the environmental impact of a consumer choice should go down since the price will have to reflect steps that address (or prevent) environmental problems.

Question 12

What does the term cradle-to-cradle mean when talking about product management?

Answer 12

Production is cyclical: “Waste” becomes the raw material once again and can be reused.

Question 13

Which of the following statements about sustainability is false?

Answer 13

In its current form, mainstream economics is the optimal model for building sustainability because external costs are built in.

Question 14

In addition to failure to consider true costs, identify and explain four erroneous assumptions that mainstream economics makes with regard to the environment.

Answer 14

1. it assumes all resources are either unlimited or substitutional (this is not true for all resources, i.e. fossil fuels are finite and we have not yet been able to come up with replacements at current levels of use) 2. ongoing economic growth is possible (despite limits for finite natural resources). 3. production can follow a linear sequence: inputs → production /product → waste (this ignores the usefulness of waste as a resource) 4. future productivity (long term value) is not as valuable as short term gain of immediate use or liquidation of a resource (this “discounting the future” allows resources to be exploited without considering the impact of their loss to future users)

Question 15

What actions did Interface Carpet use to become more sustainable?

Answer 15

Interface mimicked nature to develop their TacTiles technology (a safer glue based how a gecko lizard clings to walls and ceilings); they used a life-cycle analysis to identify impacts at every stage, allowing them to reduce waste and make better material and process choices. Interface also revolutionized its operations focusing on leasing rather than selling the product itself; this encourages Interface to produce carpet that is durable, recyclable, and also easily replaceable.

Question 16

All of the following are consistent with the law of conservation of matter except

Answer 16

if we encounter dangerous matter that we don’t want around, we can destroy it.

Question 17

Distinguish between degradable, biodegradable, and nondegradable waste. How well do plastics degrade?

Answer 17

These 3 categories differ in the degree or manner in which waste can be broken down to another form. Waste that is degradable can be broken down by physical or chemical means; biodegradable waste can be broken down by living organisms. Waste that is nondegradable resists being broken down at all and may persist in its original form. Plastics do not degrade easily — they are chemical stable and require exposure to UV light in an oxygen rich environment to start the process of breaking apart. Few, if any, microbes digest plastics so they are generally not considered to be biodegradable.

Question 18

How does waste generation relate to developmental status of countries? Why do you suppose that the regions with the highest per capita waste generation produce so much more waste than other regions?

Answer 18

The more developed a country is, the more waste it produces per person. This probably reflects excess income that can be used to buy more products and to buy products that are more processed and packaged. In lower income areas discarded items are more likely to be reclaimed and reused or recycled as well.

Question 19

True or False: Garbage decomposes more quickly in a sanitary landfill than it would in an open dump.

Answer 19

False

Question 20

Which of the following statements about incinerators is false?

Answer 20

The heat released during burning reduces the toxic and hazardous materials in the waste stream.

Question 21

Compare and contrast landfilling and composting. What are the trade-offs for each option?

Answer 21

In both, trash is allowed to decompose but the similarity ends there. Landfilled trash decomposed very slowly because water and air are excluded. This favors anaerobic bacterial breakdown which is very slow and produces methane as a byproduct. Composting puts the trash under conditions that favor aerobic bacteria and maximize decomposition rates. The result is a mulch-like soil that can be used to improve soil quality. Landfills do not produce a usable soil product but the methane can be harvested and used to produce electricity. A compost facility or area can be used indefinitely because of the fast rate of decomposition (assuming the resulting compost is removed and used). A landfill must be retired once full and may not be suitable for all land uses due to the potential presence of hazardous material buried in the landfill.

Question 22

Which of the following is a consequence of uncollected waste?

Answer 22

Air pollution

Water pollution

Flooding

Question 23

In what ways does the plastic trash in oceans harm ocean life?

Answer 23

Animals can get trapped by larger plastic debris; they may ingest smaller pieces that might cause choking, obstruction of their gut or poisoning. Plastic may also serve as attachment points for sea life, transporting species out of their natural ranges — this may be harmful for the sea life transported but more likely introduces new species to an area which may disrupt normal ecosystems.

Question 24

From an economic point of view, why is solid waste considered a mismanagement of resources?

Answer 24

Resources that are buried or lying in open dumps or burned to ash may no longer be readily available to be re-used and recycled. This reduces the matter available both to organisms in ecosystems and manufacturers looking for raw materials for production.

Question 25

True or False: Hazardous waste is an industrial waste issue and is not a problem for MSW.

Answer 25

False

Question 26

What is e-waste, and why is it a concern?

Answer 26

E-waste is electronic waste — discarding any electronic device with a circuit board such as computers, printers, cell phones, video consoles, etc. These devices contain toxic heavy metals and if not disposed of and recycled properly can expose workers or people living near the disposal sites to dangerous levels of these hazardous materials.

Question 27

Identify some hazardous substances in your home.

Answer 27

Answers will vary but could include cleaners, fluorescent light bulbs, lawn and garden chemicals, automotive chemicals, glues, and paints.

Question 28

True or False: Any vegetable based kitchen or yard scraps can be added to a compost pile but you should avoid adding meat and bones.

Answer 28

True

Question 29

The best solutions to managing waste include which one of the following?

Answer 29

Source reduction and application of natural decomposition processes

Question 30

An industrial ecologist’s goals would not include:

Answer 30

identifying points in the product life cycle at which waste products can be landfilled.

Question 31

Explain what is meant by the four Rs, in order of preference, and give an example of each.

Answer 31

The 4 Rs are steps that can be taken to reduce the overall MSW generated by an individual. In order of preference they are: Refuse: don’t use a product if not needed (i.e. don’t buy bottled water if tap water is available). Reduce: if you cannot refuse an item, then use the least amount possible (i.e. if you buy a bottle of water, refill it if possible rather than tossing it and buying another [but do so only a limited number of times to avoid exposure to chemicals in the plastic]). Re-use: Use items again to extend their life (i.e. purchase a reusable bottle for water and use it again and again; reuse disposable bottles for craft projects or as storage containers). Recycle: turn the item in for reprocessing (i.e. drop the bottle off at a recycling bin after its useful life is over).

Question 32

Which of the following is the correct hierarchy of life?

Answer 32

Individual, population, community, ecosystem, biome, biosphere

Question 33

The word niche refers to an organism’s ________, while its habitat refers to its ________.

Answer 33

role and relationships in its community; environmental surroundings

Question 34

Why do ecologists focus mainly on the study of populations, communities, and ecosystems?

Answer 34

Ecology focuses on the interactions of a species with the biotic and abiotic components of its environment. These are the levels of organization manageable enough to allow the ecologist to study interactions between and within these levels as they investigate the habitat requirements for and niche of a given species. This adds to our understanding of how a natural ecosystem functions. While biomes (or the entire ecosphere) could be studied from this same perspective (interactions), the large scale of a biome, not to mention the ecosphere, generally requires study at the ecosystem level with extrapolations made to the larger level.

Question 35

What does it mean for the Earth to be energetically open but a closed system with regard to matter?

Answer 35

Earth receives new energy inputs but not significant new matter inputs.

Question 36

Why is it essential that sustainable ecosystems rely on an energy source that is readily replenished, like sunlight, rather than nonrenewable sources, such as fossil fuels?

Answer 36

Once energy is used by an organism, it is converted to a form that is no longer useful (heat) and is therefore not considered a viable energy source for life. Any organism or ecosystem that relied on an energy source that is not readily replenished, like fossil fuels, would eventually run out.

Question 37

Which biome description is correct?

Answer 37

Grasslands receive less rainfall than forests but more than deserts.

Question 38

Which of these is an example of a population’s range of tolerance?

Answer 38

The hottest and coldest temperatures it can survive

Question 39

The population that would have the best chance of surviving an environmental change would be the one with:

Answer 39

the greatest genetic diversity.

Question 40

Using the example of spring wildflowers and the critical factor of rainfall, explain the term environmental gradient (for rainfall) and the term range of tolerance (in terms of the distribution of wildflowers within their range).

Answer 40

Rainfall amounts vary from place to place and may increase or decrease incrementally over space — such as up a mountain or away from a coastal region (an environmental gradient). A given population of a wildflower species will grow best and population will be larger in an area of optimal rainfall; nearby areas that receive slightly more or less rain, will still support the flowers but fewer individuals would be found in these less optimal habitats. Above and below certain rainfall amounts, the species will not be found — this represents the upper and lower ranges of tolerance for this species and this environmental parameter (rain).

Question 41

True or False: Plants and other producers are the only types of species that perform photosynthesis, whereas all species perform cellular respiration.

Answer 41

True

Question 42

Of the three matter cycles discussed here, the only one that does not have an atmospheric component is the __________ cycle.

Answer 42

Phosphorus

Question 43

What is the purpose of photosynthesis?

Answer 43

It produces a form of chemical energy that the plant can use as needed.

Question 44

List the steps involved in the nitrogen cycle. What would happen if a wildfire burned so hot that it sterilized the soil, killing all the microbes?

Answer 44

Atmospheric nitrogen (N2) is converted to nitrate (NO3) by lightning or through biological processes (by soil bacteria or those living symbiotically in the roots of some plants) to ammonia (NH3) — a process known as nitrogen fixation. Alternatively, nitrogen in organic matter (dead leaves, animals, etc.) is broken down by bacteria or fungi in the process of decomposition to form ammonium (NH4). The NH4 is converted to NO3 by different bacteria in a process called nitrification. Plants can take up NO3 and use it in day-to-day functioning (i.e. to make proteins or DNA) or the NO3 can be broken down by denitrifying bacteria (denitrification) which releases N2 back into the atmosphere, completing the cycle. If soil lost its microbes (soil bacteria and fungi) to fire then decomposition and nitrification would not occur and much of the ecosystem’s nitrogen would be tied up in dead matter rather than being passed onto plants to be used. Denitrification would also not occur, reducing the nitrogen returned to the atmosphere (which would not have a big impact since N2 is so abundant). Plant growth would be thus be limited to species with symbiotic nitrogen fixing bacteria in their roots or on the rate of NO3 production from lightning (a small amount). This would impact all the other species in the ecosystem since plants support the food chain in terrestrial ecosystems.

Question 45

Consider the ways in which human impact is affecting the carbon, nitrogen, and phosphorus cycles. What do these various human actions all have in common? Why might this be a concern?

Answer 45

All have resulted in the release of more carbon, nitrogen, and phosphorus into the environment in forms that can be taken up by living things. Extra nutrients can upset the natural matter cycles as they may accelerate the growth of some organisms beyond what would be seen naturally. This is especially true in areas where these nutrients might be naturally limited in supply such as aquatic ecosystems that receive extra nitrogen or phosphorus. [In the case of extra CO2, it might spur extra photosynthesis but this effect appears to be limited — the biggest impact is from the fact that CO2 is a greenhouse gas and extra amounts are contributing to climate change.]

Question 46

The number of individuals in a given area, such as an acre or a square mile, is a measurement known as __________ ___________.

Answer 46

Population density

Question 47

The concept of minimum viable population:

Answer 47

describes the smallest number of individuals needed to ensure the long-term continuation of a particular population.

Question 48

Why is it important for an ecologist to understand how a species she is studying is distributed within its ecosystem?

Answer 48

This helps her know how to search for individuals. It also serves as a starting point when assessing how the population is doing. For instance, there is no cause for alarm if individuals are not found throughout the habitat if normally they are found in a clumped distribution. On the other hand, if their distribution changes, this could signal a change in their environment. For example, if a normally randomly distributed plant appears to have a clumped distribution, then there might be something killing individuals in certain parts of the environment.

Question 49

Exponential growth of a population:

Answer 49

is often seen if a population reaches a new environment that is favorable. is a J-shaped curve on a population graph. occurs when most or all females reproduce at every opportunity and most or all offspring survive.

Question 50

Consider the roach. Why does its population size never reach its biotic potential?

Answer 50

Resistance factors limit population size.

Question 51

Kangaroo rats eat seeds and are eaten by coyotes. Under what conditions might the kangaroo rat population increase exponentially? Logistically?

Answer 51

The population size of kangaroo rats could increase if more food or nesting sites (or other limiting factor) became available or if their predator, the coyote, declined in number. Their growth would slow to logistic growth as their population size approached carrying capacity, (though as an r species they might overshoot and crash).

Question 52

True or False: Fire is an example of a density-dependent factor.

Answer 52

False

Question 53

Lesser goldfinches are small, seed-eating birds. In cities, both wild hawks and domestic cats eat these birds. Discuss several density-dependent and density-independent factors, including both growth and resistance factors, that could affect their carrying capacity.

Answer 53

Density-dependent factors would include the amount of food and number of nest sites available (critical factors), and the possibility of being captured by hawks, cats or other predators, or the spread of a disease (resistance factors). Density independent factors would include weather (which could be either a growth factor if pleasant or a resistance factor if there is either a drought or a hard, long winter) and predation by cats (a resistance factor).

Question 54

What type of species are more likely to have a population overshoot carrying capacity and then die back?

Answer 54

r-selected species

Question 55

Compare the life-history strategy of a deer mouse with that of a bear and identify each as either an r- or K-selected species.

Answer 55

Deer mice reproduce frequently, having large litters. They have a short life span, rapid growth, and are prey for many larger animals such as snakes, hawks, and coyotes. They are considered r-selected organisms. A bear is much larger and longer-lived, has only one or two offspring at a time and cares for them for a long period. Bears are omnivores, and are often predatory. They are considered K-selected organisms.

Question 56

Beavers in some areas of Michigan and Minnesota live almost exclusively on slow-growing aspen trees and can harvest them faster than the trees can reproduce. Describe how these two populations—beaver and aspen trees—undergo population fluctuations, or boom-and-bust cycles.

Answer 56

As the beaver harvest too many aspen, the aspen population drops. The beaver are then limited by the lack of the aspen trees (a growth factor), and the beaver population drops. Without the severe (resistance factor) pressure of overharvesting, the aspen population recovers. With plenty of aspen trees around, the beaver population makes a comeback.

Question 57

True or False: If predators are present in a community, top-down regulation will always trump bottom-up regulation.

Answer 57

False

Question 58

In a bottom-up regulation scenario, the size of an elk herd is determined by:

Answer 58

the amount of grass, aspen, and other food sources.

Question 59

How can it be that a single population might sometimes be controlled from the top down and other times be controlled from the bottom up? Give an example of an instance in which an elk population would be controlled by top-down regulation and another example of its control by bottom-up regulation.

Answer 59

Ecosystems are complex assemblages of biotic and abiotic factors that interact. Any difference, i.e. different species present, differences in population sizes, seasonal changes, physical disturbance such as a fire, etc., can change the relative effect of predators or food supply on the elk population. For instance, when food is scarce, predator pressure is not the biggest source of mortality, starvation is (bottom-up regulation). When spring arrives or fire sweeps through and stimulates a burst of new plant growth producing ample food, the presence of predators will likely be the most important population control mechanism in place (top-down regulation).

Question 60

Community ecologists study:

Answer 60

the relationships between species in a given area. the way species interact with their environment. the things that increase or decrease the number of species in an area.

Question 61

In ecological terms, a consumer is:

Answer 61

any organism that eats other organisms.

Question 62

Edge effects:

Answer 62

occur in the areas where two or more habitats meet.

Question 63

True or False: Ecosystem complexity increases as the variety of habitat and the number of species increases.

Answer 63

True

Question 64

Cowbirds lay their eggs in the nests of smaller forest birds such as bluebirds. The bluebirds then spend the next several weeks caring for a huge baby cowbird, which quickly kills the bluebirds’ own young. Cowbirds prefer open, disturbed areas near a forest and seldom venture far into the forest for any reason, even to lay eggs. Use the concept of edge effect to explain what happens to the populations of bluebirds when humans build roads, recreation areas, homes, and businesses in a large forest.

Answer 64

In an undisturbed forest cowbirds only parasitize the bluebird nests around the edges of the forest. As humans open up the area by removing trees and replacing them with open areas the cowbirds move into those open spaces. The cowbirds can then parasitize all nests around the edge of each smaller portion, leaving fewer and fewer bluebirds untouched in the much smaller central areas of the forest.

Question 65

An example of mutualism is:

Answer 65

a butterfly and a flowering plant.

Question 66

How do mangrove forests fit the definition of a keystone species?

Answer 66

Keystone species have an effect far beyond simply being present in an ecosystem and providing food for a few species. Mangrove forests provide shelter for many species of fish and other sea life that grow in the shallow waters among the tangled mangrove roots. They also provide many ecosystem services such as protection of the shoreline from erosion and the interwoven branches give many species of birds a place to nest.

Question 67

Explain why both species richness and species evenness are important for a healthy ecosystem.

Answer 67

Species richness is a measure of the number of different species within an ecosystem. More species means that an area will likely be more stable and less prone to disturbance should something happen to one or two of the species. Having a healthy species richness contributes to the resilience and stability of the ecosystem. Species evenness means that, at a given trophic level, there will be approximately the same number of individuals within each population. This is important to preserve the balance of populations within the ecosystem, and reduce the chance of a rare population becoming extinct.

Question 68

True or False: The construction of canals and levees to drain parts of the Everglades increased its ecosystem complexity.

Answer 68

False

Question 69

It might be hard to restore damaged ecosystems like the Everglades because:

Answer 69

some important species might no longer be present.

Question 70

What happens to the net primary productivity and to the species diversity when humans disrupt wetlands by adding more nutrients, as in the example of agriculture in the Everglades?

Answer 70

Net primary productivity is the amount of energy left after producers have used what they needed to survive; it’s the energy left for all the consumers. As synthetic nutrients run off agricultural fields they create algal blooms, which chokes off other species. Species diversity drops because many organisms cannot survive because of the competition with algae or lack of open space. [The details of eutrophication and hypoxia from algal blooms are discussed in Chapter 16.]

Question 71

Ecological succession is important because it:

Answer 71

allows ecosystems to respond to environmental changes.

Question 72

An example of when secondary succession would occur in a particular area would be after:

Answer 72

a flood has removed much of the vegetation.

Question 73

How might a restoration ecologist use an understanding of ecological succession to help repair a damaged area?

Answer 73

An ecologist who understands which species are present at any given stage of succession can use this knowledge to identify what successional stage a damaged community is currently in and then bring in the appropriate species to help succession proceed. Taking other steps to physically alter the area (remove invasives, restore natural water flow, etc.) may also make it easier for the next successional stage to take root and grow.

Question 74

True or False: Production of recyclable materials is required for recycling.

Answer 74

True

Question 75

In the United States, 54% of all garbage is categorized as ____ and ____ waste.

Answer 75

agricultural, industrial

Question 76

Choosing to buy goods with minimal packaging is an example of _________.

Answer 76

reducing

Question 77

The build-up of toxic materials in the tissues of animals is known as __________.

Answer 77

bioaccumulation

Question 78

In 2009 alone, each American produced about ___ pounds of solid waste per day. Please choose the correct answer from the following choices, and then select the submit answer button.

Answer 78

4.3

Question 79

Composting kitchen and yard waste is an example of ____________.

Answer 79

Reducing

Question 80

Sanitary landfills produce a lot of methane from __________ fermentation.

Answer 80

anaerobic

Question 81

True or False: Incinerators reduce mercury emissions from coal-burning electric plants.

Answer 81

True

Question 82

Tiny bits of plastic gather in specific areas of the world's oceans where strong currents circle around areas with very weak, or even no, currents. These regions are called __________.

Answer 82

gyres

Question 83

Incinerators reduce the volume of solid waste by about ______________.

Answer 83

80-90%

Question 84

The three main categories of biomes are marine, freshwater, and _____________.

Answer 84

terrestrial

Question 85

Denitrification involves the conversion of nitrate into _________ by bacteria, which returns nitrogen to the ___________.

Answer 85

Nitrogen gas; atmosphere

Question 86

All of the following are abiotic reservoirs for carbon EXCEPT:

Answer 86

trees

Question 87

Which of the following was NOT a problematic factor in the design of Biosphere 2?

Answer 87

insufficient levels of organic matter in the soil

Question 88

All of the following are terrestrial biomes EXCEPT:

Answer 88

kelp forest

Question 89

Two populations are more likely to coexist in a community if their __________ are dissimilar.

Answer 89

Niches

Question 90

In which zone will most individuals in a population likely NOT grow as well or be able to successfully breed?

Answer 90

zone of physiological stress

Question 91

In designing the Biosphere 2 experiment, scientists attempted to minimize the effects of limiting factors to help keep organisms within their zone of optimum range. All of the following are examples of these attempts EXCEPT:

Answer 91

regular exchange of air into and out of the biosphere to maintain optimal levels of oxygen and carbon dioxide.

Question 92

Which of the following biomes is characterized by the least amount of moisture? Please choose the correct answer from the following choices, and then select the submit answer button. Correct: tropical scrub

Answer 92

Tropical scrub

Question 93

A fisherman wants to maximize his yield in a sustainable way by catching fish during the population's fastest rate of growth. The rate of increase in population size is greatest _______.

Answer 93

at the midpoint of the S-shaped curve

Question 94

_______________ refers to local loss of a species.

Answer 94

Extirpation

Question 95

Which population distribution pattern would describe penguins competing for breeding space on a crowded beach?

Answer 95

Uniform

Question 96

After a major volcanic eruption, __________ species would likely be the first to colonize the new habitat.

Answer 96

r-selected

Question 97

True or False: The growth rates of r-adapted species are responsive to environmental conditions, which tends to keep population sizes close to carrying capacity.

Answer 97

False

Question 98

Runoff from farm fields finds its way to the Gulf of Mexico where it causes a boom in the plankton population. What limiting factor in the runoff determines the carrying capacity of the plankton?

Answer 98

nutrients

Question 99

True or False: Net primary productivity is a measure of total photosynthesis.

Answer 99

False

Question 100

_______________ refers to the progressive replacement of plant (and then animal) species in a community over time due to the changing conditions that the plants themselves create.

Answer 100

Ecological succession

Question 101

In a coral reef ecosystem, a clownfish consumes small organisms that could otherwise harm a sea anemone whose stinging cells provide protection to the clownfish from predators. This interaction is an example of ____________.

Answer 101

mutualism

Question 102

The purpose of the Comprehensive Everglades Restoration Plan (CERP) was which of the following?

Answer 102

to restore some of the natural flow of water through the Everglades and to capture a portion of the water that now flows to the ocean for South Florida cities and farms

Question 103

Which of the following is an example of a pioneer species?

Answer 103

lichen

Question 104

Most food chains have only four or five trophic levels due to the progressive loss of ________.

Answer 104

energy

Question 105

Great White Egrets and Wood Storks feed in shallow ponds and ________, which are free-flowing channels of water that develop in between sawgrass prairies. Please choose the correct answer from the following choices, and then select the submit answer button.

Answer 105

sloughs

Question 106

In the Everglades, alligators are considered to be a keystone species for which of the following reasons?

Answer 106

They increase available aquatic habitat in the dry season. They protect bird nests by preying on raccoons. Young alligators serve as prey for other predators.

Question 107

Which of the following is a climax species?

Answer 107

Oak tree

Question 108

Each trophic level contains approximately _____ of the energy of the trophic level below it.

Answer 108

10%

Question 109

Intraspecific competition is generally stronger than interspecific competition because in intraspecific competition all of the competitors share the exact same __________.

Answer 109

niche

Question 110

Which of the following is correct regarding lichens?

Answer 110

They can tolerate barren conditions. | As they live, die, and decompose, they form soil for plants that will replace them.

Question 111

Nutrient pollution in a stream causes rapid growth of one or two species of algae. As other algal species become greatly outnumbered, species _________ in the community decreases.

Answer 111

evenness

Question 112

Forest fragmentation has led to declines in songbird populations whose nests are attacked by predators that exist along forest perimeters. This is an example of an _______ effect.

Answer 112

edge

Question 113

All of the following can be found in the biosphere except: ``` rocks the ozone layer soil fish all of these are part of the biosphere ```

Answer 113

the ozone layer

Question 114

Which regulation is most likely to promote species diversity in the ecosystem?

Answer 114

top-down regulation

Question 115

A key goal of the Everglades restoration is to increase the amount of water flowing through the Everglades. This should lead to the restoration of the wood stork population, in part through the increase in the availability of nesting trees due to restoring the ____ relationship between alligators and storks.

Answer 115

commensal

Question 116

the sum of both external and internal costs of a good or service

Answer 116

true cost

Question 117

tiny bits of plastic gather in specific areas of the worlds oceans where strong currents circle around areas with very weak, or even no, currents. These regions are calles

Answer 117

gyres

Question 118

the role a species plays within its community

Answer 118

niche

Question 119

fluctuations in a population size that produce a very large population followed by a crash ....

Answer 119

boom and bust

Question 120

a species that is particularly vulnerable to ecosystem perturbations, and that, when we monitor it, can give as advance warning of the problem

Answer 120

indicator species