Deck 15: Conserving Biodiversity: Community and Ecosystem Ecology

Question 1

The variety of species in an area of interest is called

A) biomass.
B) biodiversity.
C) the trophic pyramid.
D) the ecological niche.

Answer 1

B

Question 2

The North Atlantic Right Whale, Eubalaena glacialis, was called the "right whale" because they were the best whale for early whalers to kill. They have long baleen and lots of blubber and oil. When killed, they could be towed back to land for processing because they float. They once numbered in the millions, but the entire population of the species is now less than 400. The history of the right whale is an example of

A) pollution.
B) overexploitation.
C) habitat destruction.
D) competition.

Answer 2

B

Question 3

What law was passed to address the problem of rapid species loss in the United States?

A) the Endangered Species Act of 1973
B) the Wilson-Biophilia Act of 1994
C) the Biodiversity Act of 1975
D) the Human Intervention Act of 1979

Answer 3

A

Question 4

The estimated 10 million species that exist today are thought to represent approximately ________ of the species that have ever existed on Earth.

A) 80%
B) 10%
C) 1%
D) 0.0001%

Question 5

How does the rate of extinction today compare to the rates in the past?

A) The rate is much lower today than it has been, on average, in the past.
B) The rate is about the same today as it has been, on average, in the past.
C) The rate is much higher today than it has been, on average, in the past.
D) The extinction rate today can't be estimated or calculated.

Question 6

The current rate of extinction is estimated to be ________ times greater than the calculated background rate.

A) 100
B) 50
C) 10
D) 2

Question 7

Fenway Park, home of the Boston Red Sox, is situated on land that was once a fen, a kind of wetland. The replacement of the fen is an example of

A) pollution.
B) overexploitation.
C) habitat destruction.
D) competition.

Question 8

Which of the following is an example of a nearly extinct animal in the United States?

A) black-footed ferret
B) mourning dove
C) striped skunk
D) coyote

Question 9

What is the estimated "background rate" of extinction, as calculated by scientists?

A) 10% per year
B) 1% per year
C) 0.1% per year
D) 0.0001% per year

Question 10

Although most biologists believe that many species are becoming extinct each year because of the activities of humans, relatively few species actually appear on compiled lists of extinct species. What is one reason why so few species are listed as extinct?

A) Many species are unknown to science and go extinct before they've been described.
B) There really aren't that many species that have become extinct.
C) Many species aren't listed because they aren't considered important.
D) Only extinctions that are naturally caused are listed.

Question 11

There have been ________ mass extinctions experienced on a global scale before the alarming mass extinction that's now occurring.

A) six
B) five
C) two
D) no

Question 12

Purple loosestrife, Lythrum salicaria, is a beautiful, long-stemmed wetlands species brought to the United States from Europe as an ornamental plant. In the United States, it has no predators and crowds out cattails, Typha latifolia, another wetlands plant that's a valuable resource for many species. Purple loosestrife is an example of

A) an introduced species.
B) a parasite.
C) a predator.
D) overexploitation

Question 13

Scientists have used the fossil record to estimate the average length of time that a species inhabits the Earth. This estimate is useful for assessing the impact of humans on the Earth's biological diversity because it can

A) help determine how long the human species might survive.
B) determine which species might become extinct soon, even if humans aren't involved.
C) estimate how many species extinctions are caused by human activity.
D) assure us that human activity is not the cause of most species extinctions.

Question 14

How many species "normally" go extinct each year, as estimated by scientists?

A) 1 species per thousand per year
B) 1 species per million per year
C) 1 species per billion per year
D) 1 species per year

Question 15

Global climate change is likely to increase the rate of extinction worldwide. The pollutant most implicated in this problem is

A) nitrous oxides.
B) carbon dioxide.
C) sulfur dioxides.
D) chlorofluorocarbons.

Question 16

The current rapid loss of species is considered by many scientists to be another mass extinction. This increase in extinction rate, beyond background extinction, is thought to be due to

A) a recent increase in earthquakes worldwide.
B) human population growth and the resulting habitat changes worldwide.
C) global climate change.
D) changes in the number of solar flares observed recently.

Question 17

Approximately 200 of the 300 native species of fish in Lake Victoria haven't been observed since the 1960s and are therefore probably extinct. Using the estimate of the background extinction rate, how many species of Lake Victoria fish would one expect to have naturally become extinct during the last 50 years?

A) less than 1
B) 1-10
C) 11-50
D) more than 50

Question 18

In order to be considered extinct, a species can't be found

A) at all, in the wild or in captivity at the present time.
B) at all, presently or during the past 10 years.
C) at all, presently or during the past 50 years.
D) in the wild presently but may exist in captivity.

Question 19

North America is currently experiencing an unprecedented and rapid loss of species. What is believed to be the main trigger of such events, either directly or indirectly?

A) continental drift
B) increased human population
C) climate change
D) increased predation by wild carnivores

Question 20

Life on Earth has experienced several mass extinctions. One or more of these extinctions was most likely caused by

A) an asteroid impact.
B) worldwide drought.
C) genetic drift.
D) an increase in large predatory mammals.

Question 21

The role a species plays in an ecosystem is called its

A) niche.
B) trophic level.
C) biophilia.
D) biomass.

Question 22

Which of the following threats to biodiversity isn't directly due to humans?

A) loss of habitat due to volcanic activity
B) introduction of non-native species
C) overexploitation
D) pollution

Question 23

All individuals of all species living within an area of interest represent a(n)

A) ecosystem.
B) community.
C) population.
D) trophic level.

Question 24

Which of the following would be most threatened by habitat fragmentation?

A) songbirds
B) lizards
C) mountain lions
D) antelopes

Question 25

Which of the following presents the greatest threat to biodiversity?

A) habitat loss or degradation
B) introduction of nonnative species
C) overharvesting
D) pollution

Question 26

According to the International Union for Conservation of Nature (IUCN), which of the following sequences shows groups with the highest percentage of species in danger of extinction, from most endangered (on the left)to least endangered (on the right)?

A) plants ? amphibians ? birds
B) amphibians ? birds ? plants
C) birds ? plants ? amphibians
D) plants ? birds ? amphibians

Question 27

At the current rate of habitat destruction, nearly ________ of all living species will be extinct in 50 years.

A) 1%
B) 10%
C) 25%
D) 50%

Question 28

Which group of organisms has the greatest percentage of species in danger of extinction, according to the IUCN?

A) plants
B) mammals
C) birds
D) reptiles

Question 29

A graph depicting the relationship between the size of a region and the biodiversity that it can support is called a(n)________ curve.

A) habitat loss
B) biomass
C) overexploitation
D) species-area

Question 30

The sudden loss of a ________ would necessarily cause the loss of most or all of a food web.

A) producer
B) secondary consumer
C) mutualistic species
D) keystone species

Question 31

The runoff of fertilizers from agricultural and residential areas can cause the aquatic algae in bodies of water to grow prolifically, resulting in a phenomenon called

A) competitive exclusion.
B) habitat fragmentation.
C) eutrophication.
D) overexploitation.

Question 32

Over the past 580 million years, biodiversity has

A) smoothly and steadily increased.
B) smoothly and steadily increased until the past hundred years or so.
C) generally increased but with punctuations in the pattern.
D) rapidly increased until it started to rapidly decrease in the past hundred years or so.

Question 33

The average lifespan of a species on Earth is estimated to be around ________ years.

A) 1000
B) 100,000
C) 1,000,000
D) 100,000,000

Question 34

According to this graph, when did the extinction rate in mammals exceed that of birds, if at all?

A) 1600-1649
B) 1700-1749
C) 1800-1849
D) 1900-1949

Question 35

Most of the energy contained in one trophic level is "lost" when it gets to the next trophic level. The lost energy takes the form of

A) free electrons.
B) metabolic heat.
C) potential energy, in chemical bonds.
D) kinetic energy, in the motion of consumers.

Question 36

According to this species-area curve for reptiles and amphibians on a West Indian archipelago, a 50% decrease in area will change the number of species living in the remaining area by

A) +50%
B) -50%
C) -90%
D) -10%

Question 37

An owl eating a seed-eating mouse is an example of a

A) producer.
B) primary consumer.
C) secondary consumer.
D) tertiary consumer.

Question 38

Which of the following is at the "bottom" of a trophic pyramid?

A) sunlight
B) producers
C) primary consumers
D) secondary consumers

Question 39

The lifespan of a species is the

A) span during which a living species is observed in the wild.
B) duration of time that a species doesn't change.
C) span over which fossils of a species occur.
D) period of time that it takes for an individual to mature to adulthood, reproduce, and die.

Question 40

At the current rate of habitat destruction, tropical rainforests will be reduced to ________ of their original size within 35 years, and ________ of species living there will go extinct.

A) 10%; 50%
B) 1%; 90%
C) 50%; 50%
D) 90%; 95%

Question 41

A species that has a high number of alleles for many genes that are distributed throughout the population is said to have

A) low genetic variability.
B) high genetic drift.
C) high genetic variability.
D) a large amount of inbreeding depression.

Question 42

Many species have innate preferences for the habitat to which they're most adapted. These species show signs of stress when placed in a habitat different from that in which they naturally occur. Is there any evidence that humans might have innate habitat preferences that match the environment in which humans evolved?

A) No: Humans can adapt to any environment due to their ability to manipulate their surroundings.
B) No: Humans can live in any environment; we live on every continent in the world.
C) Yes: Patients who can view nature from hospital windows have been documented to recover more quickly.
D) Yes: It's well known that people who spend more time outside live longer lives.

Question 43

Why is the preservation of ancestor species, such as Mexican teosinte (Zea diploperennis), important in the context of human welfare?

A) Edible species, such as Z. diploperennis, can be used for food if all our food crops become extinct.
B) Species such as Z. diploperennis can be used to manufacture anticancer drugs.
C) Genes from species such as Z. diploperennis can be transferred to domestic food crops to confer pest resistance.
D) Genes from species such as Z. diploperennis can be inserted into imperiled livestock varieties to help prevent them from becoming extinct.

Question 44

The entire species of North American right whales currently consists of less than 400 individuals. Through genetic testing, it has been determined that at some point in the past, probably around the time they were first protected in the beginning of the 20th century, the population had only three reproducing females. All individuals that exist today are thought to be descendants of those females. As a result, this species is vulnerable because of

A) deleterious genes.
B) low genetic variability.
C) habitat loss.
D) increased hunting pressure.

Question 45

"Colony collapse disorder" is thought to be due to an increase in ________ of honeybees.

A) predators
B) overexploitation
C) parasites
D) genetic variability

Question 46

During the 19th century, sea otters were hunted almost to the point of extinction. When the number of sea otters became very low, it was noticed that the ecosystem of kelp bed "forests" was also disappearing. It was discovered that the sea otters were predators of sea urchins, which were, in turn, predators of the kelp. When sea otters declined, the sea urchin populations grew, destroying the kelp ecosystem and the many species that depended on it. It was then understood that sea otters were ________ in this ecosystem.

A) competitors
B) producers
C) a keystone species
D) parasites

Question 47

The "psychological need" that many humans have for nature is called

A) mutualism.
B) commensalism.
C) community.
D) biophilia.

Question 48

During the 1980s, wolves were reintroduced to Yellowstone National Park after decades of absence due to attempted extermination in the early part of the 20th century. Within 20 years, not only had the wolf population increased, but there was also a dramatic increase in other species, such as aspen, cottonwood, and willow trees, beavers, warblers, insects, and fish. These changes in Yellowstone Park are examples of how important a(n)________ can be to an ecosystem.

A) keystone species
B) competitor
C) herbivore
D) parasite

Question 49

Extracts of the rosy periwinkle, Catharus roseus, have provided medicine with vincristine and vinblastine, drugs now available for treating cancer. The ability to find this species of plant and discover these drugs is a strong argument for

A) genetic engineering.
B) overexploitation.
C) preserving biodiversity.
D) supporting pharmaceutical industries.

Question 50

The U.S. Endangered Species Act that mandates decisions about the management of endangered species can be based on

A) political concerns only.
B) economic concerns only.
C) biological concerns only.
D) political, economic, and biological concerns.

Question 51

In the heart of Costa Rica there's a private reserve called Rara Avis. Here, one can hike high into the mountains of a tropical cloud forest to take guided nature hikes and learn about this unique ecosystem. This is an example of how habitats can be preserved through

A) critical habitat designation.
B) ecotourism.
C) regulations.
D) exploitation.

Question 52

There is an article in your local newspaper about an upcoming "Biodiversity Day" event at your university. Because you understand why it's important to conserve biodiversity after studying biology, you plan to attend. Your younger brother tells you he doesn't understand how the loss of a few species or habitats in town can have any impact on anyone's life. You could tell him

A) a decrease in biodiversity could result in a loss of species that could provide humans with new drugs to cure disease.
B) directly or indirectly, every species on Earth is necessary for human existence.
C) humans are not part of the web of life, but we must respect it.
D) the loss of even one species will cause the collapse of important systems that humans rely on.

Question 53

Teosinte is a wild grass in Mexico from which corn (maize)was originally domesticated. Corn that is grown commercially is probably

A) less genetically diverse than teosinte.
B) more genetically diverse than teosinte.
C) a threat to teosinte populations.
D) about as genetically diverse as teosinte.

Question 54

Salmonella enteritidis causes a food-borne illness that kills 400 to 600 Americans each year. It is found mainly in poultry products. Rather than give large doses of antibiotics to poultry, some poultry producers infect the intestinal tract of hens with a harmless bacteria, resulting in a dramatic decrease of S. enteritidis found in the chickens. In this case, the producers have used the principle of

A) mutualism.
B) predation.
C) competitive exclusion.
D) parasitism.

Question 55

Cattle egrets hitch a ride on domestic cows and eat insects that are stirred up by their activity. This is an example of

A) commensalism.
B) competition.
C) predation.
D) parasitism.

Question 56

The heath hen, found off the east coast of North America in the 18th century, is now extinct. What finally caused its extinction?

A) overexploitation
B) pollution
C) natural disasters
D) habitat loss

Question 57

Which of the following can be considered a predator?

A) dandelion
B) wood warbler
C) honey bee
D) cow

Question 58

During the last decade, the U.S. Fish and Wildlife Service has worked to reestablish the critically endangered California condor in its last stronghold, the mountains of southern California. Recently, the service has also tried to establish a second population in the Grand Canyon region of Arizona. Why would the Fish and Wildlife Service consider it a high priority to establish two populations that are geographically distant from each other?

A) Multiple condor populations reduce inbreeding.
B) Multiple condor populations provide more opportunities for people to view the endangered species, which may cause more people to be concerned with its fate.
C) Multiple condor populations reduce genetic drift within each population.
D) Multiple condor populations reduce the risk of extinction due to localized catastrophes.

Question 59

A woman is more susceptible to vaginal yeast infections when taking antibiotics because

A) the antibiotic serves as nutrition for the infectious yeast.
B) the normal bacteria in the vagina are also killed by the antibiotic and can't competitively exclude the yeast.
C) her immune system is already not functioning well due to previous infections.
D) antibiotics are lethal to most types of yeast.

Question 60

Ants from the genus Pseudomyrmex live in bull's horn acacia trees, Acacia cornigera. The ants will attack any predators of the tree. In return, the ants live protected in the thorns of the tree and eat the nectar and protein-rich secretions of the tree. This is an example of

A) parasitism.
B) mutualism.
C) competition.
D) commensalism.

Question 61

Not everyone can travel to a remote area of the world to protect a rare habitat, but there are choices each of us can make each day to reduce habitat destruction and slow the rate of species extinction. Which of the following could you do to reduce habitat destruction caused by the mining, drilling, and transport of fossil fuels?

A) eat lower on the food chain
B) only buy products that are sustainably harvested
C) carpool or use public transportation
D) keep the thermostat turned to warmer levels in winter and cooler levels in summer

Question 62

Each breed of dog is known to be susceptible to certain illnesses, such as heart problems, eye disorders, or thyroid problems. Often, dog breeders will go to great lengths to breed a dog that's unrelated to a dog they want to breed. This is because

A) individuals closely related are more likely to have the same deleterious genes.
B) individuals closely related are less likely to want to mate.
C) breeding individuals that are closely related may produce an interesting new set of characteristics.
D) breeding individuals that are closely related will result in greater fitness for the offspring.

Question 63

In 1846, the failure of "Lumper" potato crops in Ireland was due to

A) habitat loss and degradation.
B) pollution.
C) inbreeding depression.
D) lack of genetic diversity.

Question 64

Is a species that has few individuals at greater risk of extinction than a species with a large population size? Why or why not?

A) Yes. A species with few individuals is more likely to be eliminated by a reduction in population size caused by a chance environmental event like bad weather or a fire.
B) Maybe. However, there's no risk to a small population as long as genetic diversity is high.
C) Yes. A species with few individuals is likely to have a high percentage of heterozygotes. This can reduce the likelihood that the species can adaptively evolve in response to environmental changes.
D) No. Genetic drift allows small populations to avoid the loss of advantageous alleles from the population.

Question 65

A population of snakes lives in a valley. This population of snakes is 30% black and 70% brown in coloration. A dam is built to flood part of the valley, separating the snakes into two populations. West of the human-made lake, there's a very small population of all black snakes, while east of the lake, the population is much larger and retains the same percentage of black and brown coloration as before the dam was built. This is an example of

A) a homozygous population.
B) genetic drift.
C) inbreeding.
D) competitive exclusion.

Question 66

In certain areas of the world where there's a high incidence of malaria, there's also a high incidence of sickle-cell anemia. Sickle-cell anemia results from a mutation in the gene that codes for hemoglobin. Malaria is an infectious disease carried by mosquitoes. Both malaria and sickle-cell anemia can be fatal. If an individual is homozygous for normal hemoglobin, they're more prone to malaria. If an individual is homozygous for sickle-cell hemoglobin, they'll develop sickle-cell anemia. However, if an individual is heterozygous and possesses one allele for normal hemoglobin and one allele for sickle-cell hemoglobin, they're less prone to malaria and won't develop sickle-cell disease. This is an example of how

A) being heterozygous can result in greater fitness for an individual.
B) inbreeding depression can result in reduced rates of survival.
C) genetic drift can occur in small populations.
D) homozygous individuals are often unhealthy.

Question 67

The loss of heath hens in North America was an example of

A) competitive exclusion.
B) an extinction vortex.
C) a mutualism.
D) the negative effect of heterozygosity on fitness.

Question 68

To address the problem of preserving biodiversity, biologist Norman Myers and colleagues have identified various "hotspots" around the world. What exactly is a hotspot?

A) geographic areas that are warm year-round and never experience freezing temperatures
B) geographic regions where endangered species and humans come in contact with one another on a regular basis
C) areas of the world where extinction rates are significantly higher than "background" rates of extinction
D) areas around the globe where the climate and geologic events have resulted in a large number of species

Question 69

The greater fitness of individuals who carry one copy of the sickle-cell allele in areas where malaria is common is called

A) low genetic variability.
B) heterozygote advantage.
C) the benefit of mutualism.
D) competitive exclusion.

Question 70

A researcher returns from the Amazon River with 10 individuals of a species of fish and establishes a small breeding colony in her laboratory. She maintains the colony for several years (many fish generations), always maintaining the number of adult fish between 10 and 30. She notices that as generations of fish are bred, the reproductive rate decreases. What is the most likely reason for this?

A) inbreeding depression
B) increased genetic variability
C) random mutations
D) heterozygote advantage

Question 71

The best strategy for preserving biodiversity is to

A) depend on the Endangered Species Act to produce its intended consequences.
B) prevent inbreeding in small populations.
C) use genetic engineering to create new combinations of genes.
D) prevent species from becoming endangered in the first place.