Biology - Exam 5

Which is an example of a species with K-selected adaptations?

bobcat

if 2 species have very similar niches and are forced to coexist and share a limiting resource indefinitely

both species would be expected to coexist

Adaptation that enables organisms to blend into their environment thereby avoiding predation.

camouflage

The economic value of indirect ecosystems services

can greatly exceed the value derived after ecosystem conservation

The presence of a predatory species

can positively affect a prey species by having a detrimental effect on competing species

Which of the following atmospheric gases is changing the global climate?

carbon dioxide

Effects that are dependent on the size of the population and regulate the growth of populations are called ___________ effects.

density-dependent

In rain shadow, air is cooled as it rises and headed as it descends, often producing a wet and a dry side because the water-holding capacity of the air

is directly related to air temp

Oligotrophic lakes can be turned into eutrophic lakes as a result of human activities such as

introducing nutrients into the water, which stimulates plant and algal growth

Some bacteria have the ability to fix nitrogen. this means

they convert atmosperic nitrogen gas inot biologically useful forms of nitrogen

Tropical; grassland with scattered trees; seasonally dry; nutrient poor soils; large grazing mammals.

Savanna

A rancher is suspected of shooting wolves near Yellowstone National Park, and you have been enlisted to go have a chat with him. The rancher doesn't see any benefit to having the wolves there. What do you say?

"If there are no predators like wolves, just one pair of jackrabbits can quickly create a population with explosive, exponential growth. Wolves help reduce the carrying capacity, keeping the population at a reasonable level."

You and your friends have just stepped off the plane in Cusco, Peru (11,200 ft). Your friends are so eager to see Machu Picchu they want to start off hiking the Inca Trail right away and not waste any time. How do you respond?

"Waiting a few days might be smart, since it takes time to acclimate to high altitude."

Which of the following statements about the fundamental and realized niche are true? Check all that apply.

- A species' realized niche could be the same size as its fundamental niche - A species' fundamental niche can be smaller than its realized niche

Which statements about acid precipitation are accurate? Check all that apply.

- Acid rain is intermediate between point-source and diffuse pollution - Acid precipitation is a severe problem in areas with soils having high buffering capacity

In western Sweden, coastal marine ecosystems have been exposed to discharge of nutrients over several decades. As a result, algal blooms are more common.Algal mats on the sea bottom limit sunlight and alter the amount of dissolved oxygen in the water. Additionally, some algae produce toxic compounds that can enter shellfish. Furthermore, the decomposing algae produces a strong odor. Which statements below correctly match the outcomes to their effects on value of the ecosystem? Check all that apply.

- Aesthetic value is lost because the algae makes the beach ugly and smells terrible - Indirect economic value is lost because fisherman cannot catch their usual fish - Aesthetic value is gained because the algae could be used for biomass - Direct economic value is lost because the properties near the beach aren't as desirable

Which of the following are true statements about the carbon cycle? Check all that apply.

- Carbon and nitrogen fixation are both facilitated by microbes - Replacing rainforest with farms decreases atmospheric CO2 levels - Carbon cycles locally

Which of the following is a reason that conservation biologists have begun to use phylogenetic trees to assist in determining where to direct the limited resources that support conservation efforts?

- Conservation biologists do not use phylogenetic trees to make decisions about limited resource use, the diagrams are used strictly in the study of evolution

Which of the following statements about the effects of deforestation on terrestrial ecosystems are true? Check all that apply.

- Deforestation usually leads to the overaccumulation of nutrients such as nitrates/nitrites in the soil

In which of the following ways does species richness affect ecosystem function? Check all that apply.

- Low species richness can contribute to ecosystem stability - High species richness reduces overall ecosystem productivity

Which of following statements about the causes and effects of global warming are accurate? Check all that apply.

- Melting of the Artic permafrost will slow the process of global warming because of new plant growth in those areas - Carbon dioxide absorbs short wavelength radiant energy better than long wavelength radiant energy

Which of the following statements about El Niño are true?

- Occurrence of El Niño is irregular and unpredictable - Weakening in the trade winds results in more upwelling along the Peru-Ecuador coast

Without elephants, African grasslands convert to forests or to shrublands. Which of the following phrases are true statements about the elephant? Check all that apply.

- The elephant is a keystone species - If elephants went extinct, other species in the area would be unaffected - Elephants are the most abundant species on the grassland

Which of the following statements about the intermediate disturbance hypothesis are true? Check all that apply.

- The intermediate disturbance hypothesis predicts that most communities eventually reach an end-state or climax community - Intermediate disturbance should lead to increases in species richness - Disturbances tend to lead to the dominance of K-selected species

Only about ____ of the sunlight falling on plant leaves is captured by photosynthesis.

1%

Why do streams with trout have more algae?

Because the trout eat the invertebrates, which graze the algae. With fewer grazers, there are more algae

Which of the following are true about ecosystems? Check all that apply.

- There is a transfer of energy through the system and some energy is lost as heat energy - They represent the lowest level of biological organization.

Which of the following would be an expected long-term change during primary succession on glacial moraines? Check all that apply.

- decrease in soil depth

Which of the following human activities could contribute to the eutrophication of a lake? Check all that apply.

- dumping piles of leaves near a lake - planting trees around the periphery of the lake - dumping plastic trash into the lake

Human caused introductions can occur by which of the following? Check all that apply.

- plants and animals accidentally escaping from ship - international cargo ships releasing ballast water in the ocean before arriving at port

What becomes more likely to occur in a small population? Check all that apply.

- the Allee effect - increased genetic diversity - increased edge effect

A good average value for the amount of energy that reaches the next trophic level is about

10%

A Viceroy caterpillar feeds on a leaf. One day's feeding consumes 1000 calories worth of leaves. 50% of the calories are lost in its feces and 33% of the calories are used in cellular respiration.How many calories of the original intake are available to add to the caterpillar's biomass each day?

170 calories

Keeping biomagnification in mind, use the following information to estimate the level of chemical X in a large-mouth bass. One alga can accumulate 1 unit of chemical X. Each copepod eats 15 algae. A minnow consumes 10 copepods, each large-mouth bass consumes 20 minnows.

3,000 units

In a food chain with four trophic levels, what would be the energy in the top trophic level if the energy contained in the primary producer level is 40,000 kcal/m2/yr? Assume a trophic level transfer efficiency of 10%.

40 kcal/m2/yr

In a temperate zone lake, what should the temperature profile be immediately after the fall overturn?

4° C water throughout

As a general rule, how much energy is lost in the transmission of energy from one trophic level to the one immediately above it?

90%

Which of the following is an example of commensalism?

A clownfish living among the tentacles of a seam anemone

Density-dependent factors such as resource availability come into play particularly when population size is larger; density-independent factors such as natural disasters operate regardless of population size. Population density may be cyclic due to complex interactions such as resource cycles and predator effects. Populations with density-dependent regulation often are near their carrying capacity; in species with populations well below carrying capacity, natural selection may favor high rates of reproduction when resources are abundant. Can a population experience both positive and negative density-dependent effects?

A given population can experience both positive and negative density dependent effects, but not at the same time.

Life history adaptations involve may trade-offs between reproductive cost and investment in survival. These trade-offs take a variety of forms, from laying fewer than the maximum possible number of eggs to putting all energy into a single bout of reproduction. Natural selection favors maximizing lifetime reproductive success. How might the life histories of 2 species differ in one were subject to high levels of predation and the other had few predators?

A species with high levels of predation would likely exhibit an earlier age at first reproduction and shorter interbirth intervals in order to maximize its fitness under the selective pressure of the pedation. On the other hand, species with fewer predators have the luxury of waiting until they are more mature before reproducing and can increase the interbirth interval because their risk of early mortality is decreased.

What is the most reasonable conclusion that can be made from data graphed in the figure?

After low mortality early in life, mortality increases to a constant rate for the rest of life.

Populations of endotherms that live in colder climates tend to have shorter ears and limbs than populations of the same species in warm climates. This is called ____________ Rule.

Allen's

Which of the following is an example of a density-dependent effect on population growth?

An extremely hot summer in which cool burrow retreats are fewer than the number of individuals in the population

An underwater volcano has erupted, and as the lava cools a new island has formed. Which types of animal species are likely to be among the first to colonize the island? (Check all that apply)

Annelids Bats birds incests snails snakes tapirs tortoises

Which is an example of a clumped distribution?

Antelope travel in herds

Conservation hotspots are best described as

Areas with large numbers of endemic species, in may of which species are disappearing rapidly

If resources became more abundant, would you expect smaller or larger species to increase in population size more quickly?

Because of their shorter generation times, smaller species tend to reproduce more quickly, and thus would be able to respond more quickly to increased resources in the environment

If a pesticide is harmless at low concentrations and used properly, how can it become a threat to nontarget organisms?

Because the concentration of chemicals such as DDT is increase at higher trophic levels

The size at which a population stabilizes in a particular place is defined as the __________ for that species.

Carrying capacity

A developmental biologist has decided to select a crustacean species to use as a new model organism. This will allow her to ask fundamental questions about the embryology of this important group of animals. What would be the best approach to find a good species to use for experiments?

Collect pest species contaminating the wastewater system of the local marine aquarium.

Restricted by water availability; 20 degrees to 30 degrees latitude; hot sunny days, cold nights; annuals; shrubs with long roots; succulents.

Desert

Become an increasing problem as habitat size shrinks.

Edge effects

Which statement best describes the relationship between elevation and latitude?

Elevation and latitude are related because they have similar effects on temperature. As the elevation increases, the temperature of the air decreases, which is likewise with latitude.

A species goes extinct without any clear, single cause.

Extinction vortex

Which of the following is a point source of pollution?

Factory effluent pipe draining into a river

Which of the following groups do not contain any species that are autotrophs?

Fungi

Edge effects are the result of which of the following?

Habitat fragmentation or habitat shrinkage has occurred, and thus the edge of the habitat has increased in relative proportion

Primarily due to habitat destruction, pollution, human disruption, fragmentation.

Habitat loss

Regarding megafaunal extinctions, it is assumed that the driving factor was

Homo sapiens

An area with many endemic species, some of which are disappearing.

Hotspot

Which of the following whale species are recovering their population numbers as a result of whale harvesting regulations? I-right whales II-Pacific gray whales III-sperm whales IV-fin whales V-humpback whales

II and V

Suppose experimenters artificially kept the hare population at a high and constant level; what would happen to the lynx population? Conversely, if experimenters artificially kept the lynx population at a high and constant level, what would happen to the hare population?

If the hare population levels were kept high, the we would expect lynx populations to stay high as well, because lynx populations respond to food availability. if lynx populations were maintained at high level, we would expect hare populations to remain low, because increased reproduction of hares would lead to increased food for the lynxes.

A population is a group of individuals of a single species existing together in an area. A population's range, the area it occupies, changes over time. Populations, in turn, may form a network, or metapopulation, connected by individuals that move from one group to another. Within a population, the distribution of individuals can be random, uniformed, or clumped, and the distribution is determined in part by the availability of resources. How might the geographical range of a species change if populations could not exchange individuals with each other? How would your answer depend in what type of metapopulation existed?

If the population is question comprised source-sink metapopulations, then the lack of immigration into the sink population would, most likely, eventually result in the extinction of those populations. The source populations would likely then increase their geographic ranges.

Which of the following statements accurately reflects the differences between Batesian mimicry and Müllerian mimicry?

In Batesian mimicry the model must be more dangerous than the mimic; in Müllerian mimicry they are both dangerous.

How could the presence of a predator positively affect populations of a species on which it preys?

In an ecosystem with limited resources and multiple prey species, one prey species could outcompete another to exhibit in the absence of a predator. In the presence of the predator, however, the prey species that would have otherwise been driven to extinction by competitive exclusion is able to persist in the community. The predators that lower the likelihood of competitive exclusion are known as keystones predators.

Based on studies at Hubbard Brook Experimental Forest, what would be the predicted effect of clearing trees from watershea?

Increased loss of water and nutrients from a watershed

What evidence is there for the adaptive evolution of the myxoma virus?

It becomes less lethal

Demography is the quantitative study of populations. Demographic characteristic include age structure, life span, sex ratio, generation time, and birth and mortality rates. The age structure of a population and the manner in which mortality and birth rates vary among different age cohorts determine whether a population will increase or decrease in size. Will populations with higher survivorship rates always have a higher population growth rates than populations with lower survivorship rates? expail.

It depends on the initial size of the population in question; a small population with high survivorship rate will not necessarily grow faster that a large population with a lower survivorship rate.

Would natural selection favor producing many small young or few larger ones?

It depends on the situation. If only large individuals are likely to reproduce, than a few large offspring would be favored; alternatively, if body size does not affect survival or reproduction, then producing as many offspring as possible would maximize the representation of individual's genes in subsequent generations. In many cases, intermediate values are favored by natural selection.

Environmental conditions include temp, water, and light availability, and soil characteristics. When the environment changes, individual organisms use a variety of physiological, morphological, and behavioral mechanisms to adjust. Over time, adaptations to different environments may evolve in populations. How might a species respond if its environment grew steadily warmer over time?

It depends on the type of species in question. Conformers are able to adapt to their environment by adjusting their body temp and making other physiological adjustments. Over a longer period of time, individuals within a nonconforming species might not adjust to the changing environment, but we would expect the population as a whole to adapt due to natural selection.

Under what circumstances can 2 species with identical niches coexist indefinitely?

It depends on whether we are talking about fundamental niche or realized niche. 2 species can certainly have identical fundamental niches and coexist indefinitely, because they could develop different realized niches within the fundamental niche. In order for 2 species with identical realized niches to coexist indefinitely, the resources within the niche must not be limited.

In the logistic growth model, as the number of individuals in the population (N) approaches the carrying capacity (K), what happens to the intrinsic rate of growth (ri)?

It will not change

Exponential growth refers to population in which the number of individuals accelerates even when the rate of increase remains constant; it results in a population explosion. Exponential growth is eventually limited by resource availability. The size at which a population in a particular location stabilizes is defined as the carrying capacity of that location for that species. Populations often grow to the carrying capacity of their environment. What might cause a population's carrying capacity to change, how would the population respond?

Many different factors might affect the carrying capacity. For example, climate change, eneve on a relatively small scale, could have large effects on carrying capacity by altering the available water and vegetation, as well as the phenology and distribution of the vegetation. Regardless of the type of change in the environment, however, most populations will move toward carrying capacity; thus, if the carrying capacity is. lowered, the population should decrease, and if the carrying capacity is raised, the population should increase.

You are earning your Ph.D. in marine biology, studying the microbial ocean community. This year, you are shocked to discover that one of your study sites has become contaminated due to an industrial waste water pipe. This dumping is drastically raising the temperature and lowering the salinity of the water. What do you expect to find in your survey of the ecosystem, and what might you find in a survey years from now?

Many species will have decreased or disappeared from this site, but later some species may increase in population if they acquire adaptive mutations. Also you may see some new species expand into the site.

Almost all the large mammals disappeared from North America by about 10,000 years ago.

Megafaunal extinction

Which of the following statements about phosphorus cycle is correct?

Phosphorus is fixed by plants and algae

What 2 factors are most important in biome distribution?

Rainfall an temp

Which of the statements about groundwater is Not accurate?

Removal of pollutants from groundwater is easily achived

If there are many greenhouse gases, why is only carbon dioxide considered a cause of global warming?

Scientists are concerned about other causes, for example, release of methane from melting permafrost could have a significant effect on global warming

Chemicals that play the dominant role in protecting plants from being eaten by herbivores or predators are called

Secondary compunds

From a community point of view, would clear-cutting a forest be better that selective harvest of individual trees? Why?

Select harvesting of individual trees would be preferable from a community point of view. According to the intermediate disturbance hypothesis, moderate degree of disturbance, as occur in selective harvesting, increase species richness and biodiversity more than ever disturbances, such as from clear-cutting

Spruce, fir; moose; deep snow, brief summer; vast sameness; marshes, lakes, and ponds.

Taiga

High productive agricultural soils; long, cold winters; perennials; grazing mammals and burrowing rodents; fires.

Temperate grassland

Which is more important, reducing global population growth or reducing resources consumption levels in developed countries?

The 2 are closely ties together, and both are extremely important if the human population is not to exceed the Earth's carrying capacity. As population growth increases, the human population approaches the planet's carrying capacity; as consumption increases, the carrying capacity is lowered - thus, both trends must be revered.

Which of the following describe density-dependent factors?

The act to regulate population growth They are especially important in K-selected populations they do not involve biological interactions one example would be intraspecific competition for resources

Ina community, would you expect greater variation over time in abundance of animals life or plant life? Why?

The answer depends on the habitat of the community in question. Some habitats are more hospintal to animals, and other to plants. The abundance of plants and animals in most habitats is also closely tied; thus the variation in abundance of one would affect the variation in abundance of the other

Why do species exhibit different patterns of response to change in moisture?

The different soil types require very different adaptations, and thus different species are adapted to each soil type

A graduate student is studying the feeding behavior of a small octopus that must be laboriously collected from the shores of a remote island. Her intern wishes to do experiments to look at the octopus's mating behavior. Why might the graduate student veto this idea?

The octopus has semelparous reproduction, and will die after laying one batch of eggs.

While visiting the South Island of New Zealand, you notice that conditions vary sharply across the island. The West Coast is very wet and receives between 600 and 1600 mm of rainfall per year, while the East Coast only receives about 640 mm of rain per year and is very dry. What best explains this regional difference in precipitation?

The presence of mountains along the West Coast.

Why is there a sharp transition between the 2 community types?

The sharp transition between the communities occurs because 2 different habitats are in close concat with each other

Two of Darwin's finches display a character displacement when they occur as sympatric species. Which of the statements correctly interprets the graph?

The two species have different beak sizes when they occur on the same island.

Why might birth rates be density-dependent?

There are many possible reasons. Perhaps resources become limited, so that females are not able to produce as many offspring. ANother possibility is that space is limited so that, a higher populations, individuals spend more time in interactions with other individuals and squander energy that otherwise would be invested in producing and raising more young.

Very high solar energy input; temperature and moisture not limiting; high biomass, high total productivity; many species.

Tropical rain forest

True or False: An r-selected species is more likely to become an invasive pest than a K-selected species.

True

When given the opportunity, lizards regulate their body temp. to maintain a temp. optimal for physiological functioning. Would lizards in open habitats exhibit different escape behaviors from those of lizards in shaded forest?

Very possibly. How fast a lizard runs is a function of its body temp.

Would fertilization with animal manure be less disruptive that fertilization with purified chemicals? why?

Yes, fertilization with natural materials such a manure is less disruptive to the ecosystem than its chemical fertilization. Many chemical fertilizers, for example, contain higher levels of phosphates that does manure, and thus chemical fertilization as disrupted the natural global phosphorus cycle

COuld top-down and bottom-up effects occur simultaneously?

Yes, there are certain situations in ecosystems in which the top predators in one trophic chain affect the lower trophic levels, and within the same ecosystem the primary producers affect the higher trophic levels within another trophic chain

bottom-up effects on trophic structures result from

a limitation of energy flowing to the net higher trophic level

According to MacArthur and Wilson's island biogeography theory, which of the following would be expected to have the smallest species richness?

a small island far from the mainland

A friend asks you for a definition of endemic because she is writing a history paper and this word keeps occurring in the literature in reference to bison on the Great Plains of the United States. Your response is that the word endemic means

a species that lives in only one area of Earth.

During the 1960s, a group of scientists in the northeastern United States conducted an experiment at Hubbard Brook, New Hampshire. A 38-acre watershed was completely deforested and the runoff (water flow) monitored for several years. It was compared to an adjacent watershed that was left untouched. The scientists collected data during those years and found

a tremendous increase in the amount of runoff and nitrogen release from Hubbard Brook compared to the control.

Addition of a primary carnivore to an ecosystem can sometimes influence the whole ecosystem. This process is called

a trophic cascade.

Lakes become eutrophic by

accumulation of organic matter

A species colonizes an island, goes through a phase of exponential growth, and reaches the carrying capacity of the island. At what stage is the growth rate slowest?

after reaching k

Ecologists are concerned about amphibian populations because

amphibians are very sensitive to environmental change—they may be indicating serious problems.

According to the trophic cascade hypothesis, the removal of carnivores from an ecosystem may result in

an increase in the number of herbivores and a decrease number in the amount of vegetation

A(n) ________ is a permeable underground layer of rock, sand, and gravel saturated with groundwater.

aquifer

Deep-sea hydrothermal vent communities

are built on the energy produced by the activity if chemoautotrophs that oxidize sulfur

when populations are drastically reduced in size, genetic diversity and heterozygosity

are likely to decrease, enhancing the probability of extinction

Suppose you wanted to keep annual bluegrass in your room as a houseplant. Suppose, too, that you wanted to buy an individual plant that was likely to live as long as possible. What age plant would you buy? How might the shape of the survivorship curve affect your answer?

based on the survivorship curve of meadow grass, the older the plant, the less likely it is to survive. It would be best to choose a plant that is very young to ensure the longest survival as a houseplant. A survivorship curve that is the shaped like a type I curve, in which most individuals survive to an old age and then die, would also lead you to select a younger plant. A type III survivorship curve, in which only a few individuals manage to survive to an older age, would suggest the selection of a middle-aged plant that had survived the early stages of life, since it would also be more likely to survive to old age.

It is a situation in which a palatable organism resembles another kind of organism that is distasteful or toxic.

batesian mimicry

A ____________ cycle is a cyclic path that involves both biological and chemical processes of an ecosystem.

biogeochemical

Inverted ecological pyramids of real systems usually involve

biomass

In the carbon cycle, ______ from the atmosphere is used in photosynthesis to synthesize carbon-containing organic molecules in a process called ______.

carbon dioxide; carbon fixation

Cattle egrets follow African ungulates such as African buffalo around and catch insects that the buffalo flush out. Oxpeckers perch on the backs of buffalo and feed on ectoparasites that infest the buffalo. Which one of the following shows the ecological interaction that the buffalo has with each bird?

cattle egret: commensalism; oxpecker: mutualism

Is the process by which different kinds of organisms adjust to one another by genetic change over long periods of time.

coevolution

When a predator preferentially eates the superior competitor in a pair of competing species,

coexistence of the competing species is more likely

In India, golden jackals that have been expelled from their pack have been known to attach themselves to a particular tiger, trailing it at a safe distance in order to feed on the big cat's kills. What type of relationship exists between the jackal and the tiger?

commensalism

All organisms living together in a place are called a

community

Two organisms trying to utilize the same resource is called

competition

During the mid 1930s, G. F. Gause studied competition among three species of Paramecium. Through his experiments he formulated a principle of

competitive exclusion

If the energy of the sun no longer reached Earth, the primary productivity of which of the following ecosystems would be least affected?

deep sea hydrothermal vent

Organisms that possess this property are poisonous, sting, or are otherwise harmful; commonly black, yellow, and red in color.

defense coloration

Vampire squid (Vampyroteuthisinfernalis) are deep-sea cephalopods with features similar to both octopus and squid. Extensive video recordings show the diet of the vampire squid consists of items like crustacean remains and fecal pellets. Which of the following terms describes the position of the vampire squid in the deep-sea trophic pyramid?

detritivore

The Coriolis effect

drives global wind and ocean circulation patterns

During an ecology field trip to a lake, your professor asks you to take temperature readings at various depths and record your data. At 5 meters, you note a temperature of 25°C and at 10 meters you record a temperature of 10°C. Readings at 20 meters and below stay fairly consistent around 8°C. The temperature readings of 25°C, 10°C, and 8°C represent the

epilimnion, thermocline, and hypolimnion

Succession happens because species in the habitat alter that habitat in ways that assist other species. There are three dynamic concepts that are of critical importance for succession to take place. They are

establishment, facilitation, and inhibition.

According to the idea of coevolution between predator and prey, when a prey species evolves a novel defense against a predator,

evolution of a predator response should be favored by natural selection

the levels of DDT in the environment were having a detrimental effect on eggs (causing the eggshells to be too thin) that were being laid by the female falcons.

fewer endemic species are found on islands.

Photosynthesis organisms

fix carbon dioxide and release carbon dioxide

The process of examining the genomes of animals and plants for useful genes is

gene prospecting

A major problem with hotspots is humans moving in and causing

habitat destruction

the potential for social interaction among individuals should maximized when individuals

have a clumped distribution in their enviroment

Oligotrophic lakes have

high oxygen, and low nutrient availability

The difference between exponential and logistic growth rates is that

in logistic growth, emigration and immigration are unimportant

SPecies diverity

increases with latitude as you move away from the equator to the Artic

Studies that demonstrate that species living in an ecological community change independently of one another is space and time

indicate that the species' realized niches are regulated by different aspects of the environment

In populations subjected to high levels of predation,

individuals should invest greatly in reproduction because their chance of surviving to another breeding season is low

Competition between species is called ____________ competition.

interspecific

Resource partitioning by sympatric species

is more common in herbivores than in carnivores

The way in which an organism utilizes its environment may be called

its niche

An organism whose decline or removal from a habitat causes many other species numbers to change dramatically is called __________ species.

keystone

A species whose effect on the composition of a community is greater than expected based on its abundance can be called a

keystone species

Thermal stratification in a lake

leads to higher oxygen in surface versus deep water

What would be the best approach to curbing excessive human population growth?

lowering birth rates through education and family planning

In the last 20 years one concern of scientists who study amphibians is that

many species are declining or have gone extinct in recent years.

A captive-breeding program followed by release to the wild

may be successful when combined with proper regulation and habitat restoration

Species that are the first colonists in a habitat undergoing primary succession

may change their habitat in a way that favors the invasion of other species

The elimination of a predators by humans

may increase the population size of a prey species if that pray's population was being regulated by predation from the predator

A life history trade-off between clutch size and offspring size

means that as clutch size increase, offspring size decrease

Source-sink metapopulations are distinct from other types of metapopulations because

populations with negative growth rates are a part of the former

Nitrogen is often a limiting nutrient in may ecosystems because

most organisms cannot use nitrogen in its elemental form

To effectively address the biodiversity crisis, the protection of individual species

must be used in concert with a principal of ecosystem management and restoration

A relationship in which both members benefit is called

mutualism

In a population in which individuals are uniformly distributed

natural selection should favor traits that maximize the ability to compete for resources

The relatively shallow part of the ocean extending from the low tide mark to the edge of the continental shelf is called the

neritic zone

In order for mimicry to be effective in protecting a species from predation, it must

occur in a palatable species that looks like a distasteful species

A mountain range along the coast of a continent is located perpendicular to the prevailing sea breeze. Which one of the following describes an area where the rain shadow is located?

on the leeward side of the mountain where cool, dry air is descending

Which one of the following ecosystems is most likely to show an inverted biomass pyramid but a normal energy pyramid?

open ocean

The West African black rhino, one of four subspecies of rhinoceros, was declared extinct in 2006. Their horns were believed by many to hold medicinal value. What is the most likely reason for the extinction of the West African black rhino?

overexploitation

Most of the ultraviolet radiation reaching the upper atmosphere is absorbed by

ozone

Insects that lay eggs on living hosts are called

parasitoids

Drifting freely in the upper, well-illuminated waters of the ocean, a diverse biological community exists, primarily consisting of microscopic organisms called

phytoplankton

Biological magnification occurs when

pollutants increase in concentration in tissues at higher trophic levels

Temperate grasslands and temperate deciduous forests are two different biomes that are located in the same latitudes. Which one of the following abiotic conditions is most likely to account for the differences in their community composition?

precipitation

A wolf that feeds on moose and elk would be classified within which trophic level?

primary carnivore

In the food chain below, what does the garden spider represent? crabgrass—cricket—garden spider—blue jay—red-tailed hawk

primary carnivore

Competition shapes communities because there are usually limited

resources

In the food chain below, what does the blue jay represent? crabgrass—cricket—garden spider—blue jay—red-tailed hawk

secondary carnivore

Chemical compounds produced by plants that are not components of major metabolic pathways.

secondary chemical compounds

The equilibrium model of island biogeography suggests all of the following except

smaller islands have lower rates of extinction

Organisms such as lizards that need to maintain body temperature through external means do so by

sunbathing

Rhizosphaera needle cast is a fungal disease that affects spruce trees. Which of the following biomes would be most severely affected by an outbreak of this disease?

taiga

Prairie is another name for a

temperate grassland

The various endemic cichlid species of Lake Victoria have suffered losses in their population numbers and species due to the introduction of

the Nile perch

The difference in the fundamental niche and the realized niche is

the fundamental niche is the entire niche that a species is capable of using while the realized niche is just what is being occupied.

A scientist studied peregrine falcons to determine why the numbers of birds was declining. She determined that

the levels of DDT in the environment were having a detrimental effect on eggs (causing the eggshells to be too thin) that were being laid by the female falcons.

When ecologist talk about the cost of reproduction they mean

the reproduction in future reproductive outputs as a consequence of current reproduction

When New York City was given a choice to make regarding its drinking water

they chose ecosystem maintenance over development

A nonpoisonous scarlet king snake has red, black, and yellow bands of color similar to those of the poisonous eastern coral snake. what type of mimicry is being exhibited?

this is an example of batesian mimicry, in which a non poisonous species evolves coloration similar to that of a poisonous species

Photosynthetic organisms of the open oceans are confined to the upper

two hundred meters

What kind of population spacing would you expect for a species that is strongly territorial?

uniform

If the Earth were not tilted on it axis of rotation, the annual cycle of seasons in the northern and southern hemispheres

would not exist