Ecology Review 1

Of or referring to the physical or nonliving environment.

Abiotic

An organism's adjustment of its physiology, morphology, or behavior to lessen the effect of an environmental change and minimize the associated stress.

Acclimatization

A physiological, morphological, or behavioral trait with an underlying genetic basis that enhances the survival and reproduction of its bearers in their environment.

Adaptation

A physiological, morphological, or behavioral trait with an underlying genetic basis that enhances the survival and reproduction of its bearers in their environment.

Adaption

Different community development scenarios, or community states, that are possible at the same location under similar environmental conditions.

Alternative stable states

An organism that converts energy from sunlight or from inorganic chemical compounds in the environment into chemical energy stored in the carbon-carbon bonds of organic compounds.

Autotroph

An organism that converts energy from sunlight or from inorganic chemical compounds in the environment into chemical energy stored in the carbon-carbon bonds of organic compounds.

C3 Photosynthetic Pathway

The diversity of important ecological entities that span multiple spatial scales, from genes to species to communities.

Biodiversity

The highest level of biological organization, consisting of all living organisms on Earth plus the environments in which they live; located between the lithosphere and the troposphere

Biosphere

Of or referring to the living components of an environment

Biotic

Interactions of the native species in a community with non-native species that exclude or slow the growth of those non-native species

Biotic Resistance

A zone close to a surface where a flow of fluid, usually air, encounters resistance and becomes turbulent.

Boundary Layer

A biochemical pathway involving the daytime uptake of CO2 by the enzyme phosphoenol pyruvate carboxylase (PEPcase) in mesophyll cells; the carbon is then transferred as a four-carbon acid to the bundle sheath cells, where CO2 is released to the Calvin cycle for sugar synthesis.

C4 Photosynthetic Pathway

The biochemical pathway used by photosynthetic and chemosynthetic organisms to fix carbon and synthesize sugars.

Calvin Cycle

The use of energy from inorganic chemical compounds to fix CO2 and produce carbohydrates using the Calvin cycle; also called chemolithotrophy.

Chemosynthesis

Any force that impedes the movement of compounds such as water or gases such as carbon dioxide along an energy or concentration gradient; its inverse is conductance.

Resistance

Directional change in climate over a period of three decades or longer.

Climate Change

The range of climate variables, including temperature, humidity, precipitation, and solar radiation, that are associated with a species geographic distribution.

Climate Envelope

The last stage of succession that is thought to be stable until disturbances or stresses shift the community back to earlier successional stages.

Climax Stage

A group of interacting species that occur together at the same place and time

Community

A group of interacting species that occur together at the same place and time.

Community

The set of characteristics that shape a community, including the number, competition, and abundance of species

Community structure

A process in which the best competitor uses limiting resources that the weaker competitor requires ultimately causing a decline in the weaker competitor's population growth to the point of extinction.

Competitive Displacement

A hypothesis proposing that as the species richness of a community increases, there is a linear increase in the positive effects of those species on community function. Compare idiosyncratic hypothesis and redundancy hypothesis

Complementary Hypothesis

An organism that obtains its energy by eating other organisms or their remains.

Consumer

standard scientific approach in which an experimental group (that has the factor being tested) is compared with a control group (that lacks the factor being tested).

Controlled Experiment

A photosynthetic pathway in which CO2 is fixed and stored as an organic acid at night, then released to the Calvin cycle during the day.

Crassulacean acid metabolism

The use of limiting resources by different species in a community in different ways.

Resource Partioning

An interaction that occurs between two species, such as predation, competition, or a positive interaction

Direct Interaction

An abiotic event that kills or damages some individuals and thereby creates opportunities for other individuals to grow and reproduce.

Disturbance

A state in which little or no metabolic activity occurs.

Dormancy

A hypothesis proposing that species diversity in communities is maintained by a "lottery" in which resources made available by the effects of disturbance, stress, or predation are captured at random by recruits from a larger pool of potential colonists.

Lottery Model

An elaboration of the intermediate disturbance hypothesis proposing that species diversity is maximized when the level of disturbance and the rate of competitive displacement are roughly equivalent.

Dynamic Equilibrium Model

The environmental temperature at which the heat loss of an endotherm triggers an increase in metabolic heat generation.

Lower Critical Temperature

A hypothesis proposing that species can coexist in a community by using the same resources, but in differing proportions

Resource Ratio Hypothesis

The scientific study of interactions between organisms and their environment.

Ecology

All the organisms in a given area as well as the physical environment in which they live; can include one or more communities.

Ecosystem

A species that influences its community by creating, modifying or maintaining physical habitat for itself and other species

Ecosystem Engineer

A population with adaptations to unique local environmental conditions.

Ecotype

An animal that regulates its body temperature primarily through energy exchange with its external environment.

Ectotherm

An animal that regulates its body temperature primarily through internal metabolic heat generation.

Endotherm

An interdisciplinary field of study that incorporates concepts from the natural sciences (including ecology) and the social sciences (e.g., politics, economics, ethics), focused on how people affect the environment and how we can address environmental problems. Answer 1

Environmental Science

Abiotic agents of change include negative species interactions such as competition, predation, and trampling. Ecosystem engineers and keystone species are relatively common abiotic agents of change. Select one: True False

False

Biotic agents of change can act as disturbances (injuring or killing organisms) or as stresses (reducing growth, reproduction, and survival of organisms. Select one: True False

False

Human activities have caused regime shifts in communities but these regime shifts are always reversible. Select one: True False

False

The uptake of the gaseous form of a compound, including CO2 in photosynthesis and N2 in nitrogen fixation, by organisms for use in metabolic functions.

Fixation

A diagram showing the connections between organisms and the food they consume

Food Web

Early ecologists were fascinated with succession but disagreed about whether succession proceeded in deterministic or random ways. Select one: True False

True

A species that has large, community-wide effects on the habitat or food of other species by virtue of its size or abundance

Foundation Species

A subset of a community that includes species that function in similar ways, but do not necessarily use the same resources.

Functional Group

Events in the natural world are interconnected. For example, evidence suggests that warming sea temperatures as a result of global warming may be causing feminization of a large sea turtle population that inhabits the Great Barrier Reef. This connection between global warming and sex determination may result the complete feminization of this population (i.e., no male sea turtles produced). Select one: True False

True

A subset of a community that includes species that use the same resources, whether or not they are taxonomically related.

Guild

An organism that obtains energy by consuming energy-rich organic compounds made by other organisms.

Heterotroph

Torpor lasting several weeks during the winter; a strategy that is possible only for animals that have access to enough food and can store enough energy reserves.

Hibernation

Non-trophic interactions, such as competition and some positive interactions, that occur within a trophic level.

Horizontal Interaction

A possible answer to a question developed using previous knowledge or intuition.

Hypothesis

The inability of a community that has undergone change to shift back to the original community type, even when the original conditions are restored.

Hysterisis

A hypothesis proposing that as the species richness of a community increases, community function will vary idiosyncratically as the result of some species having stronger effects on the community than others.

Idiosyncratic Hypothesis

An interaction in which the relationship between two species is mediated by a third (or more) species.

Indirect Interaction

A measure of the effect of one species (the interactor) on the abundance of another species (the target species)

Interaction Strength

A concept that describes both the trophic (vertical) and non trophic (horizontal) interactions among the species in a traditional food web.

Interaction Web

A hypothesis proposing that species diversity in communities should be greatest at intermediate levels of disturbance (or stress or predation) because competitive exclusion at low levels of disturbance and mortality at high levels of disturbance should reduce species diversity.

Intermediate Disturbance Hypothesis

A strong interactor species that has an effect on energy flow and community structure that is disproportionate to its small size, abundance, or biomass

Keystone Species

An area that is spatially heterogeneous in one or more features of the environment, such as the number or arrangement of different habitat types; typically includes multiple ecosystems.

Landscape

Individual organisms can respond to environmental change through, acclimatization, a short-term adjustment of the organism's physiology, morphology, or behavior that lessens the effect of the change and minimizes the associated stress. Select one: True False

True

The energy associated with attractive forces on the surfaces of large molecules inside cells or on the surfaces of soil particles.

Matric Potential

The process by which individuals with certain heritable characteristics tend to survive and reproduce more successfully than other individuals because of those characteristics.

Natural Selection

The amount of energy per unit of time that producers capture by photosynthesis and chemosynthesis, minus the amount they use in cellular respiration.

Net Primary Productivity (NPP)

The cyclic movement of nutrients between organisms and the physical environment.

Nutrient Cycle

An acclimatization response to changing water availability or salinity in terrestrial and aquatic environments that involves changing the solute concentration, and thus the osmotic potential, of the cell.

Osmotic Adjustment

The energy associated with dissolved solutes.

Osmotic Potential

Succession that involves the colonization of habitats devoid of life.

Primary Succession

A chemical reaction in photosynthetic organisms in which the enzyme rubisco takes up O2, leading to the breakdown of sugars, the release of CO2, and a net loss of energy.

Photorespiration

A process that uses sunlight to provide the energy needed to take up CO2 and synthesize sugars

Photosynthesis

The study of the interactions between organisms and the physical environment that influence their survival and persistence.

Physiological Ecology

A group of individuals of the same species that live within a particular area and interact with one another.

Population

The energy associated with the exertion of pressure; has a positive value if pressure is exerted on the system and a negative value if the system is under tension.

Pressure Potential

An organism that can produce its own food by photosynthesis or chemosynthesis; also called a primary producer or autotroph.

Producer

The presence of hairs on the surface of an organism.

Pubescence

A graph that plots the proportional abundance of each species in a community relative to the others in rank order, from most abundance to least abundant

Rank Abundance Curve

A hypothesis that assumes an upper limit on the positive effect of species richness on community function because once species richness reaches some threshold, the functions of species in the community will overlap.

Redundancy Hypothesis

Having the same function in a community as other species in the community within a larger functional group

Redundant species

The performance of each treatment of a controlled experiment, including the control, more than once.

Replication

The spatial or temporal dimension at which ecological observations are collected.

Scale

Succession that involves the reestablishment of a community in which some, but not all, of the organisms have been destroyed.

Secondary Succession

The index most commonly used to describe species diversity quantitatively.

Shannon Index

A measure that combines the number of species (species richness) in a community and their relative abundances compared with one another (species evenness)

Species Diversity

A graph that plots species richness as a function of the total number of individuals that are present with each additional sample

Species accumulation curve

The relative abundances of different species compared to one another in a community

Species evenness

When a community retains, or returns to, its original structure and function after some perturbation.

Stability

A pore in plant tissues, usually leaves, surrounded by specialized guard cells that control its opening and closing.

Stomate

An abiotic factor that results in a decrease in the rate of an important physiological process, thereby lowering the potential for an organism's growth, reproduction, or survival; the condition caused by such a factor.

Stress

Water flows along energy gradients determined by solute concentration (osmotic potential), pressure or tension (pressure potential), and the attractive force of surfaces (matric potential). Select one: True False

True

The process of change in the species composition of a community over time as a result of abiotic and biotic agents of change.

Succession

What is one reason that amphibians are especially good biological indicators of environmental conditions? Select one: a. They live in both terrestrial and aquatic environments. b. It is difficult for pollutants to pass through their skin. c. They are declining in number. d. They can tolerate high levels of pollution.

a. They live in both terrestrial and aquatic environments.

A state of dormancy in which endotherms drop their lower critical temperature and associated metabolic rate.

Torpor

A change in the rate of consumption at one trophic level that results in a series of changes in species abundance or composition at lower trophic levels.

Trophic Cascade

An interaction in which a consumer is indirectly facilitated by a positive interaction between its prey or food plant and another species

Trophic Facilitation

Aquatic animals that are hyperosmotic to their environment must uptake solutes from the environment to compensate for solute losses to the surrounding water. Select one: True False

True

Aquatic animals that are hypoosmotic to the surrounding water must expend energy to excrete salts against an osmotic gradient. Select one: True False

True

Ecologists are concerned about the establishment of invasive species in new areas because invasive species Select one: a. can have large ecological effects in their new communities. b. that become established are easy to control. c. are often toxic. d. always cause a decline in biological diversity of the communities they invade.

a. can have large ecological effects in their new communities.

Maron and Vila (2001) found that native herbivores Select one: a. can reduce the spread of non-native plants. b. never exclude species from communities. c. always co-exist with non-natives. d. always completely exclude non-native species from communities.

a. can reduce the spread of non-native plants.

The experiments of Kenward and colleagues with New Caledonian crows showed that Select one: a. crows that have not been exposed to other toolmaking birds are unable to make tools. b. all groups of crows living on the island use the same set of tools. c. the ability of crows to manufacture tools is at least partially inherited. d. captive crows are unable to make tools.

a. crows that have not been exposed to other toolmaking birds are unable to make tools.

A mouse is sitting in the sun. Solar radiation provides a net intake of energy of 30 milliwatts per minute, and infrared radiation provides an additional net input of 8 milliwatts per minute. Conductive and convective outputs are a combined 55 milliwatts per minute. There is no detectable change in heat from evaporation. Assuming that the mouse is maintaining a constant temperature, how much heat must it be generating per minute? Select one: a. 17 milliwatts b. 25 milliwatts c. 33 milliwatts d. 38 milliwatts

a. 17 milliwatts

Which of the following is an example of chemical energy transfer? Select one: a. A lion metabolizing the lamb it ate b. The heating of a mouse when it sits on hot pavement c. The heating of a lake by the sun d. The heating of the atmosphere by solar radiation

a. A lion metabolizing the lamb it ate

In the study by Jennifer Hughes and colleagues, in which community did it appear that the species richness had been adequately sampled? Select one: a. A plant community from a forest in Michigan b. East Amazonian soil bacteria c. Human oral bacteria d. Costa Rican moths

a. A plant community from a forest in Michigan

What takes place during the second step of photosynthesis, referred to as the "carbon reactions"? Select one: a. CO2 is fixed, producing carbohydrates. b. CO2 is oxidized by solar radiation. c. Water is split to provide electrons to synthesize ATP and NADPH. d. Chlorophyll is oxidized by water.

a. CO2 is fixed, producing carbohydrates.

Which principle is best supported by the results of Sutherland's studies in which fish predators were excluded from a marine fouling community? Select one: a. Communities can follow different successional paths and display alternative states. b. Predation is a relatively unimportant factor in succession in marine communities. c. In most marine systems, the tolerance model accurately predicts successional outcomes. d. Facilitation is most important in early succession, whereas inhibition becomes more important in later stages.

a. Communities can follow different successional paths and display alternative states.

Which of the following is a biotic factor that can be an agent of change? Select one: a. Competition b. Drought c. A hurricane d. A forest fire

a. Competition

Which conclusion was the primary finding of Buss and Jackson's study of coral-associated invertebrates and algae in Jamaica? Select one: a. Competitive networks can be circular. b. Environmental context can change the outcome of species interactions. c. Diversity is maintained due to the existence of keystone species. d. Species diversity estimates vary with sampling effort.

a. Competitive networks can be circular.

The earliest autotrophs on Earth were probably not photosynthetic but instead were chemosynthetic bacteria or archaea. In what way was the early atmosphere different from the atmosphere today? Select one: a. It was richer in CO2 and methane. b. It lacked CO2. c. It lacked inorganic substrates. d. It contained large amounts of ozone.

a. It was richer in CO2 and methane.

Which statement about food webs is true? Select one: a. Most food webs do not include information about symbiotic relationships. b. All species occupy only a single trophic level in a food web. c. Food webs generally provide much information about the strengths of interactions across trophic levels. d. Food webs provide information about trophic and non-trophic interactions.

a. Most food webs do not include information about symbiotic relationships.

Which type of succession involves colonization of habitats devoid of life? Select one: a. Primary b. Secondary c. Pristine d. Abiotic

a. Primary

Which statement about zoonotic disease transmission is false? Select one: a. Small mammal species diversity decline is linked with increased hantavirus infections in deer mice. b. An experiment in Panama showed small-mammal diversity removal increased infected hosts relative to control plots. c. Research showed that deer mouse populations decreased triggering the transmission of the Sin Nombre virus infections in humans. d. Species diversity could buffer the transmission of zoonotic pathogens to wildlife and ultimately humans.

a. Small mammal species diversity decline is linked with increased hantavirus infections in deer mice.

Which value can be measured the most easily? Select one: a. Species richness b. Species evenness c. Species diversity d. Species evenness and species richness are equally easy to measure.

a. Species richness

Which quality is a biotic feature of the environment? Select one: a. The density of consumers b. The average minimum temperature at night c. The number of days during which at least 1 mm of rain falls d. The pH of the soils

a. The density of consumers

Which model assumes the absence of competitive hierarchies among species? Select one: a. The lottery model b. The dynamic equilibrium model c. The intermediate disturbance model d. Both a and b

a. The lottery model

Which statement about zebra mussels in North America is true? Select one: a. They arrived in North America from ballast water discharged into the Great Lakes. b. They are predators that hunt their food. c. They usually do not foul infrastructure. d. They can dramatically increase populations of phytoplankton.

a. They arrived in North America from ballast water discharged into the Great Lakes.

In terrestrial plants, the closing of stomates to reduce water loss when water is scarce has two major trade-offs: photosynthesis is limited due to _______, and membranes can be damaged by _______. Select one: a. limited CO2 uptake; energy accumulation b. increased retention of H2O; energy accumulation c. limited CO2 uptake; an increase in enzyme concentrations d. limited retention of H2O; increased transpiration

a. limited CO2 uptake; energy accumulation

Plants with bacterial symbionts that fix _______ are often important players in _______ stages of succession. Select one: a. nitrogen; early b. phosphorus; late c. sulfur; early d. phosphorus; early

a. nitrogen; early

If Cowles is correct about succession, then Select one: a. space can be substituted for time. b. the unique conditions in particular locations are of great importance. c. we do not have the ability to make inferences about the changes in communities over time scales that span centuries. d. succession is usually unpredictable.

a. space can be substituted for time.

In contrast to C3 plants, C4 plants have _______, which keeps the CO2 concentration high where the Calvin cycle operates. Select one: a. well-differentiated mesophyll cells and bundle sheath tissue with a waxy coating b. a waxy coating around the xylem c. spongy mesophyll cells d. stomata in the lower and upper epidermis

a. well-differentiated mesophyll cells and bundle sheath tissue with a waxy coating

Which statement about ecology is true? Select one: a. All organisms living in the same area are strongly connected to one another. b. All organisms interact with features in their environments. c. Organisms can only be directly connected through their ties to shared features of the environment. d. Both b and c

b. All organisms interact with features in their environments.

In the dunes near Lake Michigan studied by Cowles, the dominant plant species in the early stages of succession was Select one: a. spike grass. b. American beach grass. c. Indiana dune grass. d. Michigan cord grass.

b. American beach grass.

Which early ecologist maintained that plant communities are analogous to "superorganisms"? Select one: a. Henry Cowles b. Fredrick Clements c. Henry Gleason d. F. Stuart Chapin

b. Fredrick Clements

Which statement about the amphibians that colonized the area around Mount St. Helens after the eruption is true? Select one: a. The frog Rana cascadae was the most important animal ecosystem engineer in the community. b. Frogs and salamanders started to colonize the area within the first few years of the eruption. c. By the year 2000, the species diversity of amphibians had reached pre-eruption levels. d. Both a and b

b. Frogs and salamanders started to colonize the area within the first few years of the eruption.

Which statement about the difference between a competitive network and a competitive hierarchy is true? Select one: a. A competitive network comprises more species than interaction networks. b. In a competitive hierarchy, one species dominates the interaction; in an interaction network, no one species dominates the interaction. c. The interactions are stronger in a competitive network than in interaction networks. d. In a competitive hierarchy, indirect species interactions always buffer strong competition; in interaction networks, they do not.

b. In a competitive hierarchy, one species dominates the interaction; in an interaction network, no one species dominates the interaction.

Which statement best describes the difference between the theoretical concept of a community and the ways in which communities are delineated in practice? Select one: a. In theory, a community is defined only by abiotic factors of the area; in practice, communities are delineated by biological attributes as well. b. In theory, communities consist of all species present; in practice, biologists usually study only a subset of the species. c. In theory, communities can be defined by physical or biological characteristics, but in practice, these characteristics are difficult to measure and are not used. d. There is no difference between the theoretical concept of a community and how it is defined in practice.

b. In theory, communities consist of all species present; in practice, biologists usually study only a subset of the species.

Which statement about Huston's dynamic equilibrium model is most accurate? Select one: a. It is another name for the intermediate disturbance hypothesis. b. It is an elaboration of the intermediate disturbance hypothesis and predicts that species diversity will be highest in communities with low levels of both disturbance and competitive displacement. c. It is an elaboration of the intermediate disturbance hypothesis and predicts that species diversity will be highest in communities with high levels of both disturbance and competitive displacement. d. It states that the intermediate disturbance hypothesis pertains only to terrestrial ecosystems.

b. It is an elaboration of the intermediate disturbance hypothesis and predicts that species diversity will be highest in communities with low levels of both disturbance and competitive displacement.

Which hypothesis about the benefits of photorespiration was supported by Kozaki and Takeba's experiment with tobacco plants, in which the plants were genetically altered to elevate and lower their rates of photorespiration? Select one: a. Photorespiration takes up the excess O2 that builds up at high light levels. b. Photorespiration protects the plant's photosynthetic machinery at high light levels. c. Photorespiration cools the plant at high light levels. d. Photorespiration releases CO2, which in turn increases the rate of photosynthesis.

b. Photorespiration protects the plant's photosynthetic machinery at high light levels.

Which statement is an assumption of the resource partitioning theory? Select one: a. Species differ in their intrinsic population growth rates. b. Resources are limiting. c. The different species in a community interact with one another directly. d. Both a and b

b. Resources are limiting.

Consider three different scenarios. In all three scenarios, the environment fluctuates between one of two states: state 1, in which a larger fish species outcompetes a smaller fish species; and state 2, in which the smaller species outcompetes the larger species. In all three scenarios, the time spent in either state, as well as the degree to which one species outcompetes the other, is roughly the same. Thus, on average, the larger and the smaller species are comparable in their competitive abilities. In scenario A, environments switch every three years, on average, and competitive exclusion usually takes four months. In scenario B, environments switch about every five months, and competitive exclusion usually takes about four months. In scenario C, the environments switch about every three weeks, and competitive exclusion usually takes about two years. Assuming that Hutchinson's model is correct, in which of these scenarios is long-term persistence of both species most likely? Select one: a. Scenario A only b. Scenario B only c. Scenario C only d. It is equally likely in scenarios A and B.

b. Scenario B only

Which statement about the studies by Mary Power and colleagues on California rivers is true? Select one: a. In drought years the number of trophic levels increased. b. Species, such as the steelhead, that are keystone predators during normal years are minor players in the food web during drought years. c. The alga Cladophora completely died out during droughts. d. Species interactions remained constant despite changes in environmental conditions.

b. Species, such as the steelhead, that are keystone predators during normal years are minor players in the food web during drought years.

Which statement about early primary succession is false? Select one: a. The process can be very slow. b. The first colonists typically cannot withstand much physiological stress. c. The first colonizers usually can modify the habitat to benefit their growth and reproduction. d. The first colonists typically face hostile conditions.

b. The first colonists typically cannot withstand much physiological stress.

What is the "paradox of the plankton"? Select one: a. The number of phytoplankton species increased after zebra mussels invaded the Mississippi river basin. b. There are many more species of phytoplankton in temperate freshwater lakes than would be expected given the limited types of resources. c. Disturbance seems to decrease the number of species of phytoplankton in temperate freshwater lakes. d. The species of phytoplankton found in temperate freshwater lakes is remarkably constant across North America despite their apparently limited dispersal ability.

b. There are many more species of phytoplankton in temperate freshwater lakes than would be expected given the limited types of resources.

Suppose that following a lava flow, pine grass (a hypothetical species) is the first species to colonize the area. Chemicals produced by pine grass change the soil chemistry in the environment, but these chemicals have little or no effect on subsequent colonization by later species. Which model would best explain this scenario of succession? Select one: a. Inhibition b. Tolerance c. Facilitation d. Both a and b

b. Tolerance

A tourist travels to the Himalayas. At first, she has difficulty hiking due to shortness of breath, but after a week, her performance has improved. This is most likely an example of _______ to lower partial pressure of oxygen. The lower oxygen condition is also known as _______. Select one: a. adaptation; hyperoxia b. acclimatization; hypoxia c. acclimatization; hyperoxia d. adaptation; hypothermia

b. acclimatization; hypoxia

An association of populations of different species living in the same area is called a(n) Select one: a. population. b. community. c. ecosystem. d. biosphere.

b. community.

.A grounds crew manager of a large park has the particular task of guarding the land against invading species. He is aware that a certain weedy plant could not withstand average winter conditions in the area, but it could survive during a particularly mild winter. The most conservative conclusion the manager might come to about the risk of this plant as an invasive species is that the plant Select one: a. could potentially be an invader if climate change causes colder winters. b. could potentially be an invader due to variation in physiological capabilities among individual plants. c. could potentially be an invader due to biotic resistance. d. does not pose a threat.

b. could potentially be an invader due to variation in physiological capabilities among individual plants.

Orchid species that have lost their ability to photosynthesize, and instead parasitize fungi for their energy needs, are examples of Select one: a. chemosynthetic organisms. b. holoparasites. c. hyperparasites. d. hemiparasites.

b. holoparasites

Cougars prey on both white-tailed deer and mule deer. Because of their shared predator, each deer species' abundance is affected by the presence of the other deer species. The white-tailed and mule deer are engaged in a(n) Select one: a. direct interaction. b. indirect interaction. c. trophic facilitation. d. predator-prey relationship.

b. indirect interaction.

When you touch something hot, your hand becomes warm; this is an example of the transfer of _______ energy. Select one: a. autotrophic b. kinetic c. chemical d. radiant

b. kinetic

In 1993 an unknown virus infecting humans was determined to be a pathogen carried by Select one: a. bats. b. mice. c. skunks. d. mosquitoes.

b. mice.

According to Hacker and Gaines's extension of the intermediate disturbance hypothesis, mutualisms and other positive interactions should _______ species diversity, especially at _______ levels of disturbance. Select one: a. promote; low b. promote; high c. decrease; low d. decrease; high

b. promote; high

The biochemical pathway most commonly used by plants and chemosynthetic bacteria to fix CO2 in order to synthesize carbohydrates is Select one: a. glycolysis. b. the Calvin cycle. c. the Hatch‒Slack‒Kortschack pathway. d. the Krebs cycle.

b. the Calvin cycle

Tilman's experiments with two species of diatoms showed that the species could coexist Select one: a. when the ratio of silica to phosphorus was very low. b. when the ratio of silica to phosphorus was at an intermediate level. c. when the ratio of silica to phosphorus was very high. d. under all ratios of silica to phosphorus.

b. when the ratio of silica to phosphorus was at an intermediate level.

In a grassland ecosystem, plants capture 180 units per day of solar energy, and they use up 70 units per day in respiration. Animals consume about 20 units per day of the plants. The NPP of this system is _______ units per day. Select one: a. 70 b. 90 c. 110 d. 180

c. 110

Which sequence represents the correct order of levels of biological organization, from largest to smallest? Select one: a. Biosphere; ecosystem; population; community b. Biosphere; population; ecosystem; community c. Biosphere; ecosystem; community; population d. Ecosystem; biosphere; community; population

c. Biosphere; ecosystem; community; population

Which statement about change in communities is true? Select one: a. Only biotic factors can be agents of change. b. Only abiotic factors can be agents of change. c. Disturbances create opportunities for some species to grow or reproduce due to the injury or death of other individuals. d. "Stress" and "disturbance" are interchangeable words that describe the same processes.

c. Disturbances create opportunities for some species to grow or reproduce due to the injury or death of other individuals.

You are in Glacier Bay. Starting at a location dominated by alders, you would most likely first run into the _______ stage if you went toward the glacier's edge. You would most likely first run into the _______ stage if you went away from the glacier's edge. Select one: a. pioneer; Dryas b. pioneer; spruce c. Dryas; spruce d. spruce; Dryas

c. Dryas; spruce

Which statement about adaptation is true? Select one: a. Genetic adaptations evolve within individuals during an individual's lifetime. b. "Adaptation" is another word for "acclimatization." c. Genetic variation within a population is a requirement for the evolution of adaptations. d. Both a and b

c. Genetic variation within a population is a requirement for the evolution of adaptations.

Which statement describes a limitation of a species accumulation curve in terms of its ability to determine whether species diversity has been adequately sampled? Select one: a. It can be used only for a community of large spatial scale. b. It can be used only for a community of small spatial scale. c. It assumes that the sampling methods are consistent throughout the study. d. It assumes a high Shannon index.

c. It assumes that the sampling methods are consistent throughout the study.

Which statement about the "killer alga," Caulerpa taxifolia, is false? Select one: a. It was unintentionally released into the Mediterranean by the Oceanographic Museum of Monaco. b. Its invasive range extends at least as far as Spain on the west and Croatia on the east. c. It is toxic to humans and other mammals. d. It has evolved cold resistance.

c. It is toxic to humans and other mammals.

Rubisco, which is an important catalyst in photosynthesis, is also a catalyst in the process of photorespiration. Photorespiration differs from photosynthesis in that in photorespiration _______ is taken up, _______ is released, and there is a net _______ of energy. Select one: a. CO2; O2; loss b. CO2; O2; gain c. O2; CO2; loss d. O2; CO2; gain

c. O2; CO2; loss

Which statement best summarizes Elton's views on succession? Select one: a. Plant communities are like "superorganisms"—that is, groups of species that work together in a mutual effort toward some deterministic end. b. Each community has its own predictable life history; left undisturbed, the community will ultimately reach a stable, predetermined endpoint. c. Organisms and the environment interact to shape the direction that succession will take. d. Communities are like an organism with various interacting parts; responses to the prevailing conditions by individual species matter little.

c. Organisms and the environment interact to shape the direction that succession will take.

What was Hutchinson's explanation for the "paradox of the plankton"? Select one: a. Predation checked the superior competitor. b. The coexisting species used different amounts of limiting resources. c. Seasonal changes prevented any one species from competitively excluding the others. d. Migration from other lakes maintained species diversity.

c. Seasonal changes prevented any one species from competitively excluding the others.

Which statement about the concept of natural selection is false? Select one: a. Natural selection is an evolutionary process whereby different individuals survive and reproduce at different rates based on particular characteristics they possess. b. According to the concept of natural selection, those who survive and reproduce at a greater rate pass on more of their genes to the next generation, as compared to those who have a lower survival and reproduction rate. c. The frequency of a trait favored by natural selection will increase over generations whether the trait is heritable or not. d. Only natural selection can produce adaptations consistently.

c. The frequency of a trait favored by natural selection will increase over generations whether the trait is heritable or not.

Suppose that individuals of a particular genetic strain of Drosophila melanogaster reproduce at an earlier age than do other strains of this species. As a consequence, they tend to die sooner. Which maxim does this phenomenon exemplify? Select one: a. Everything goes somewhere. b. No population can increase in size forever. c. There is no such thing as a free lunch. d. Space matters.

c. There is no such thing as a free lunch.

Which statement about keystone predators is true? Select one: a. They usually are abundant in number and/or have disproportionately high biomass. b. They usually influence primary producers directly. c. They usually influence primary producers indirectly. d. They are the same as foundation species.

c. They usually influence primary producers indirectly.

What takes place during the first step of photosynthesis, referred to as the "light-driven reactions"? Select one: a. CO2 is fixed, producing carbohydrates. b. CO2 is oxidized by solar radiation. c. Water is split to provide electrons to synthesize ATP and NADPH. d. Chlorophyll is oxidized by water.

c. Water is split to provide electrons to synthesize ATP and NADPH.

Among vertebrates, _______ can survive a long winter in a semi-frozen state. Select one: a. all species of amphibians and turtles b. all species of frogs c. a few species of frogs, salamanders, and turtles d. one species of frog

c. a few species of frogs, salamanders, and turtles

According to Hutchinson's model for coexistence of plankton species, coexistence is likely when environmental change takes place _______ the process _______. Select one: a. much more quickly than; of competitive exclusion b. at about the same rate as; by which natural selection fixes new alleles c. at about the same rate as; of competitive exclusion d. much more slowly than; of competitive exclusion

c. at about the same rate as; of competitive exclusion

In the CAM pathway, CO2 uptake occurs _______ and the Calvin cycle occurs _______. Select one: a. in the mesophyll cell; in the bundle sheath b. in the epidermis; in the bundle sheath c. at night; during the day d. during the day; at night

c. at night; during the day

Robert MacArthur showed that different species of warblers in New England forests Select one: a. cannot coexist indefinitely. b. coexist because they utilize different types of trees. c. coexist because they utilize different parts of the same trees. d. coexist because they utilize the same trees at different times of the day.

c. coexist because they utilize different parts of the same trees.

Menge and colleagues performed experiments in which they exposed some populations of mussels to sea stars and excluded sea stars from other mussel populations. Suppose two populations of mussels are the same size prior to treatment, and after treatment there are 600 mussels in the treatment without sea stars and 200 mussels in the treatment with sea stars. Suppose further that the sea star population consists of 10 individuals. What is the per capita interaction strength of sea stars on mussels? Select one: a. ln (3/10) b. (ln 600)/(ln 200) c. ln (0.33/10) d. ln (0.33/200)

c. ln (0.33/10)

In their tests of the extension of the intermediate disturbance hypothesis in a New England salt marsh, Hacker and Gaines found that in the low intertidal zone, physiological stress was _______ and species diversity was _______. Select one: a. high; low b. high; high c. low; high d. low; low

c. low; high

The tolerance and the inhibition models of primary succession hold different assumptions about the Select one: a. nature of the effects that the early colonizing species have on other early colonizing species. b. nature of the disturbances and the opportunities they provide. c. nature of the effects that the early colonizers have on late colonizing species. d. strength of the disturbances and the extent of their impact on the habitat.

c. nature of the effects that the early colonizers have on late colonizing species.

Species that feed on more than one trophic level are called Select one: a. tertiary consumers. b. herbivores. c. omnivores. d. primary producers.

c. omnivores.

Lions prey on animals such as zebras and wildebeest, which feed primarily on grasses. Lions thus should be considered Select one: a. primary consumers. b. herbivores. c. secondary consumers. d. tertiary consumers

c. secondary consumers.

The Shannon index is a measure of Select one: a. interaction strength. b. species richness alone. c. species diversity. d. the extent of trophic facilitation.

c. species diversity.

Alternative stable states most often arise Select one: a. in terrestrial ecosystems. b. in intertidal zones. c. when there are strong interactions among species. d. under the tolerance model of succession.

c. when there are strong interactions among species.

Sets of competitive interactions involving multiple species in which every species negatively interacts with every other species

competitive network

Estimates show that oceans absorb about _______ of all the atmospheric CO2. Select one: a. 1% b. 10% c. 40% d. 48%

d. 48%

Which trait cannot evolve by natural selection? Select one: a. A trait that increases the time during which females are reproductively competent b. A trait that increases the ability of an organism to survive high temperatures, at the expensive of survival at low temperatures c. A trait that increases the ability of an organism to survive low temperatures, at the expensive of survival at high temperatures d. A trait that is the result of an individual's life experiences and does not have a genetic basis

d. A trait that is the result of an individual's life experiences and does not have a genetic basis

How does climate change impact invasive species? Select one: a. It alters the environment they land in. b. It changes the distribution of species. c. It alters competitive interactions. d. All of the above

d. All of the above

Which human activity can bring about shifts in communities to alternative stable states? Select one: a. Habitat destruction b. Introduction of invasive species c. Overexploitation of native species d. All of the above

d. All of the above

Which of the following is a factor determining the species composition of communities? Select one: a. Regional species pools b. Abiotic conditions c. The nature of interactions between introduced species and species already in the community d. All of the above can be factors determining species composition.

d. All of the above can be factors determining species composition.

According to the concept of resource partitioning, which attribute of a community would tend to lead to lower species richness? Select one: a. Low specialization of species b. A broad resource spectrum c. A narrow resource spectrum with high specialization d. Both a and b

d. Both a and b

An experiment by Alsterberg and colleagues showed that with ocean acidification and warming, the biomass of benthic microalgae Select one: a. did not change with omnivores. b. declined without omnivores. c. increased with omnivores. d. Both a and b

d. Both a and b

How did the generation of oxygen by early photosynthesizing organisms alter the conditions on early Earth? Select one: a. It led to the creation of the ozone layer, protecting organisms from high-energy UV radiation. b. It led to a warmer atmosphere. c. It allowed for aerobic respiration. d. Both a and c

d. Both a and c

What do chemosynthesis and photosynthesis have in common? Select one: a. They both result in the storage of energy in carbon-carbon bonds. b. They both require sunlight. c. They both fix carbon. d. Both a and c

d. Both a and c

Although beavers are relatively rare, they have considerable influence over species interactions in communities in which they are present because of the dams that they construct. The beaver is thus an example of a(n) Select one: a. foundation species. b. ecosystem engineer. c. keystone species. d. Both b and c

d. Both b and c

The _______ pathways, which provide high concentrations of CO2 to the Calvin cycle, substantially reduce photorespiration. Select one: a. C3 and C4 photosynthetic b. C4 photosynthetic and ATP c. ATP and CAM d. CAM and C4 photosynthetic

d. CAM and C4 photosynthetic

The first person to recognize the importance of disturbance in promoting species diversity was _______, who noted that more species persisted on a section of lawn that was mowed regularly than on one that was not mowed. Select one: a. Robert Paine b. G. E. Hutchinson c. David Tilman d. Charles Darwin

d. Charles Darwin

Which of the following is not an abiotic factor that can be an agent of change? Select one: a. A hurricane b. Acid rain c. An ice storm d. Digging

d. Digging

Which statement about the study of ecology is false? Select one: a. It describes how organisms affect the environment. b. It describes how the environment affects organisms. c. It studies how biotic and abiotic factors affect each other. d. Humans are not part of its subject matter.

d. Humans are not part of its subject matter.

What is the primary difference between interaction webs and food webs? Select one: a. Interaction webs include more trophic levels. b. Interaction webs include fewer trophic levels. c. Interaction webs do not consider primary producers, whereas food webs do. d. Interaction webs include non-trophic interactions; food webs do not.

d. Interaction webs include non-trophic interactions; food webs do not.

In their studies of a salt marsh community, Sally Hacker and colleagues found that removing _______ led to a(n) _______. Select one: a. Juncus; increase in the abundance of Iva b. Iva; increase in the abundance of Juncus c. Juncus; increase in the abundance of aphids through indirect effects d. Juncus; decrease in the abundance of aphids through indirect effects

d. Juncus; decrease in the abundance of aphids through indirect effects

According to the _______ model of succession, the early successional species modify the environment so as to facilitate the subsequent colonization of other early colonizing species. Select one: a. facilitation b. tolerance c. inhibition d. None of the above

d. None of the above

Members of the same functional group must belong to the same Select one: a. guild. b. trophic level. c. taxonomic group. d. None of the above

d. None of the above

Why do researchers think that "sponging" behavior in bottlenose dolphins is a learned trait? Select one: a. The behavior occurs in all individuals in the population. b. The behavior occurs only in females. c. The behavior is due to a sex-linked gene. d. The behavior appears to be socially transmitted through the maternal line.

d. The behavior appears to be socially transmitted through the maternal line.

Which statement about ecological studies is true? Select one: a. They usually focus on individuals. b. They usually focus on populations. c. They usually focus on ecosystems. d. The can focus on any level of biological organization from individuals up through to the level of the biosphere.

d. The can focus on any level of biological organization from individuals up through to the level of the biosphere.

Which of the following is an example of something that could be predicted with information on a species' "climate envelope"? Select one: a. The reproductive rate of that species b. The growth rate of the species c. The survival rate of the species d. The range that the species could potentially inhabit

d. The range that the species could potentially inhabit

Organisms that can convert energy from sunlight or from inorganic compounds in their environment, without having to consume other organisms for their energy needs, are called Select one: a. heterotrophs. b. monotrophs. c. decomposers. d. autotrophs.

d. autotrophs.

The use of specialized bacteria to help break down a toxic organic pesticide spilled during an industrial accident is an example of Select one: a. the practical application of the Hatch-Slack-Kortschack pathway. b. metabolomics. c. biological control. d. bioremediation.

d. bioremediation.

A weed that is ordinarily invasive is unable to establish itself in a meadow community because the roots of other plant species produce chemicals that retard its growth. This is an example of Select one: a. resource partitioning. b. resilience. c. competitive displacement. d. biotic resistance.

d. biotic resistance.

According to the intermediate disturbance hypothesis, Select one: a. high disturbance levels increase species diversity due to high mortality. b. high disturbance levels reduce species diversity due to competitive exclusion. c. intermediate disturbance levels increase species diversity due to resource partitioning. d. low or absent disturbance levels reduce species diversity due to competitive exclusion.

d. low or absent disturbance levels reduce species diversity due to competitive exclusion.

Suppose that a late succession plant that is surrounded by early succession plants grows at a rate of 0.5 cm per day. If the early succession plants are removed experimentally, the late succession plants are observed to grow at a rate of 0.9 cm per day. This experiment shows that the early succession plants have a _______ effect on the late succession plants, and this observation is most consistent with the _______ model of succession. Select one: a. positive; facilitation b. positive; inhibition c. negative; facilitation d. negative; inhibition

d. negative; inhibition

Robert and John MacArthur found that in both tropical and temperate habitats, bird species diversity _______ as plant diversity increased and _______ as foliage height diversity increased. Select one: a. significantly increased; significantly increased b. significantly increased; showed no statistically significant change c. showed no statistically significant change; significantly decreased d. showed no statistically significant change; significantly increased

d. showed no statistically significant change; significantly increased

Sousa's studies of intertidal zones in southern California showed that Select one: a. succession was driven primarily by facilitation. b. the first species to colonize was the same across patches. c. the first species to colonize varied across patches. d. succession was driven primarily by inhibition.

d. succession was driven primarily by inhibition.

In their manipulative studies of succession in a New England salt marsh, Bertness and Shumway altered salt stress in certain fields by Select one: a. adding salt. b. introducing microbes that filter out salt. c. shading the soil's surface. d. watering the fields with fresh water.

d. watering the fields with fresh water.

The first stage of primary succession.

pioneer stage

The number of species in a community

species richness

A group of species that obtain energy in similar ways, classified by the number of feeding steps by which the group is removed from the primary producers which are the first trophic level

trophic level