Living in the Environment 18th Edition Miller - Test Bank

CHAPTER 5—BIODIVERSITY, SPECIES INTERACTIONS, AND POPULATION CONTROL

MULTIPLE CHOICE

1.What was the primary reason the southern sea otter nearly went extinct by the early 1900s?

a. They scared the tourists.

b. They have thick, luxurious fur.

c. They were ruining the kelp beds.

d. They were eating all the shellfish.

e. They raided valuable bird nests.

ANS:BPTS:1

TOP: 5-0 Core Case Study: The Southern Sea Otter: A Species in Recovery

KEY:Bloom’s: Remember

2.The primary reason why southern sea otter recovery is important is because they ____.

a. are educational

b. are a keystone species

c. encourage tourism

d. eliminate common pests

e. have luxurious, thick fur

ANS:BPTS:1

TOP: 5-0 Core Case Study: The Southern Sea Otter: A Species in Recovery

KEY:Bloom’s: Remember

3.Species can, over a long period of time, develop adaptations that allow them to reduce or avoid competition by sharing resources. This is called ____.

a. competitive exclusion principle

b. resource partitioning

c. population distribution

d. interspecific competition

e. mimicry

ANS: B PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Understand

4.Some prey species discourage predators with chemicals that are poisonous, irritating, foul smelling, or bad tasting. What is this called?

a. chemotoxicity

b. biological warfare

c. chemical warfare

d. behavioral warfare

e. behavioral strategies

ANS: C PTS: 1 TOP: 5-1 How Do Species Interact?

KEY: Bloom’s: Understand NOT: New

5.When populations of two different species interact over long periods of time, changes in the gene pool of one species can lead to changes in the gene pool of the other. What is this called?

a. competition

b. coevolution

c. coincidence

d. commensalism

e. predation

ANS: B PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Remember

6.Bats prey on certain species of moths by using high frequency echolocation to locate their prey.  Certain moths have evolved ears that can hear these frequencies allowing them to escape. This is an example of ____.

a. mimicry

b. coevolution

c. a behavioral strategy

d. commensalism

e. mutualism

ANS: B PTS: 1 TOP: 5-1 How Do Species Interact?

KEY: Bloom’s: Apply NOT: New

7.What is said to occur when one organism feeds on another organism by living on or in the other organism?

a. interspecific competition

b. predation

c. parasitism

d. mutualism

e. commensalism

ANS: C PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Remember

8.Parasites ____.

a. rarely kill their hosts

b. are usually larger than their hosts

c. must be internal to their hosts

d. may strengthen their hosts over a long period of time

e. are usually microscopic

ANS: A PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Understand

9.From the ____ point of view, parasites are harmful, but from the ____ perspective, parasites can promote diversity.

a. population’s; host’s

b. host’s; population’s

c. predator’s; prey’s

d. prey’s; predator’s

e. community’s; individual’s

ANS: B PTS: 1 TOP: 5-1 How Do Species Interact?

KEY: Bloom’s: Apply NOT: New

10.When two species behave in ways that benefit both by providing each with food, shelter, or some other resource, it is called ____.

a. mimicry

b. coevolution

c. parasitism

d. commensalism

e. mutualism

ANS: E PTS: 1 TOP: 5-1 How Do Species Interact?

KEY: Bloom’s: Understand NOT: New

11.The relationship between clownfish and sea anemone is called ____.

a. interspecific competition

b. predation

c. parasitism

d. mutualism

e. commensalism

ANS: D PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Understand

12.The relationship between bacteria that live in the digestive systems of animals, such as humans, is ____.

a. interspecific competition

b. predation

c. parasitism

d. mutualism

e. commensalism

ANS: D PTS: 1 TOP: 5-1 How Do Species Interact?

KEY: Bloom’s: Understand NOT: New

13.What occurs when an interaction benefits one species but has little, if any, effect on the other?

a. interspecific competition

b. predation

c. parasitism

d. mutualism

e. commensalism

ANS: E PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Remember

14.Plants such as bromeliads share a commensalism interaction with large trees in tropical and subtropical forests by attaching to the trunks or branches of the trees. The bromeliads are an example of ____.

a. parasites

b. opportunistic parasites

c. epiphytes

d. prey

e. herbivores

ANS: C PTS: 1 TOP: 5-1 How Do Species Interact?

KEY: Bloom’s: Apply NOT: Modified

15.Which of the following is not considered a form of nondestructive behavior?

a. reducing competition by foraging at different times

b. reducing competition by foraging in different places

c. orchids attached to branches of forest trees

d. using the energy or body of another organisms as a food source

e. bacteria breaking down food for a host and having a sheltered habitat

ANS: D PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Analyze

16.What occurs when members of two or more species interact to gain access to the same limited resources?

a. interspecific competition

b. predation

c. parasitism

d. mutualism

e. commensalism

ANS: A PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Understand

17.What is the most common interaction between species?

a. competition

b. predation

c. parasitism

d. mutualism

e. commensalism

ANS: A PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Remember

18.If multiple species find themselves competing for the same resource, the competition can be reduced by which of the following?

a. camouflage

b. cooperation

c. resource partitioning

d. resource expansion

e. mimicry

ANS: C PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Understand

19.The non-poisonous ____ butterfly gains protection by looking like the bad-tasting ____ butterfly, which is a protective device known as ____.

a. monarch; viceroy; camouflage

b. monarch; zebra swallowtail; camouflage

c. viceroy; zebra swallowtail; mimicry

d. viceroy; monarch; mimicry

e. viceroy; monarch; camouflage

ANS: D PTS: 1 TOP: Figure 5-6 | 5-1 How Do Species Interact?

KEY:Bloom’s:Evaluate

20.Kelp forests help reduce ____ by blunting the force of incoming waves and trapping some of the outgoing sand.

a. runoff

b. shore erosion

c. coastal pollution

d. tidal waves

e. tidal pools

ANS: B PTS: 1 TOP: Science Focus 5-1 Threats to Kelp Forests

KEY: Bloom’s: Understand NOT: New

21.Kelp forests are a very important ecosystem in marine waters by supporting important biodiversity. These kelp forests are threatened by all of the following except _____.

a. water pollution containing herbicides

b. sea urchins

c. southern sea otters

d. global warming

e. water pollution containing fertilizers

ANS: C PTS: 1 TOP: Science Focus 5-1 Threats to Kelp Forests

KEY:Bloom’s: Analyze

22.What is a population’s distribution of individuals among various age groups called?

a. reproductive structure

b. genetic structure

c. age structure

d. reproductive composition

e. age composition

ANS: C PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: New

23.What describes an organism that is too old to reproduce?

a. prereproductive

b. reproductive

c. postreproductive

d. nonreproductive

e. elderly

ANS: C PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: New

24.Each population in an ecosystem has a ____ to variations in its physical and chemical environment.

a. low tolerance

b. high tolerance

c. range of tolerance

d. high resilience

e. low resilience

ANS: C PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: New

25.Too much or too little of any physical or chemical factor can prevent the growth of a population, even if all other factors are at or near the optimum conditions. What is this ecological principle?

a. tolerance

b. limiting factor

c. resilience

d. persistence

e. optimal level

ANS: B PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: New

26.What is the number of individuals in a population found within a defined area or volume that can limit the size of some populations?

a. population density

b. population control

c. the range of tolerance

d. the age structure

e. the optimum population level

ANS: A PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: New

27.Some species that tend to reproduce later in life and have a small number of offspring with long life spans ____.

a. have high population growth rates

b. have high environmental resistance

c. have low environmental resistance

d. are unlikely to ever face extinction

e. are vulnerable to extinction

ANS: E PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Analyze NOT: New

28.There are ____ limits to population growth in nature.

a. never

b. sometimes

c. always

d. low

e. high

ANS: C PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: New

29.The maximum population of a given species that a particular habitat can sustain indefinitely is the definition of ____.

a. logistic growth

b. environmental resistance

c. exponential growth

d. carrying capacity

e. biotic potential

ANS: D PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Remember NOT: Modified

30.When plotting the number of individuals in a population against time, the data yield a J-shaped curve. What does this curve indicate?

a. logistic growth

b. environmental resistance

c. exponential growth

d. carrying capacity

e. biotic potential

ANS: C PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Apply

31.Exponential growth followed by a steady decrease in population growth until the population size stabilizes is typical of ____.

a. logistic growth

b. environmental resistance

c. exponential growth

d. carrying capacity

e. biotic potential

ANS: A PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Analyze NOT: Modified

32.By 1900, white-tailed deer populations in the U.S. were reduced to about ____, but now, since laws have been passed to protect them and their natural predators have nearly been eliminated, their population is over ____ in the U.S.

a. 500; 1 million

b. 5,000; 1 million

c. 50,000; 5 million

d. 50,000; 25 million

e. 100,000; 10 million

ANS: D PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: New

33.What would cause a population to overshoot its carrying capacity?

a. an increase in predators

b. a decrease in birth rates

c. an increase in emigration

d. a decrease in environmental pressures

e. a reproductive time lag between birth and death rates

ANS: E PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Understand

34.A group of interbreeding individuals of the same species in the same geographic region is called a(n) ____.

a. community

b. population

c. ecosystem

d. biosphere

e. biome

ANS: B PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Remember

35.What is the most common distribution of populations?

a. random

b. uniform

c. clumped

d. circles

e. none of these

ANS: C PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Remember

36.A population increases through birth and ____.

a. assimilation

b. integration

c. socialization

d. emigration

e. immigration

ANS: E PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: New

37.Emigration is the ____.

a. arrival of individuals into an established population

b. arrival movement of individuals into an uninhabited area

c. departure movement of individuals from a population to another area

d. repeated movement into and out of an area

e. lack of immigration into an area

ANS: C PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: Modified

38.Kelp forests are composed of large concentrations of a(n) ____.

a. algae

b. phytoplankton

c. seaweed

d. trees

e. anemone

ANS: C PTS: 1 TOP: Science Focus 5-1 Threats to Kelp Forests

KEY: Bloom’s: Remember NOT: New

39.Which of the following has caused the population of the southern sea otters to fluctuate?

a. decline in population of orcas

b. parasites from house cats

c. parasites from dolphins

d. high reproductive rates

e. extinction of algal species

ANS:BPTS:1

TOP: Science Focus 5-2 Why Do California’s Sea Otters Face an Uncertain Future?

KEY: Bloom’s: Analyze NOT: Modified

40.What is succession that begins in an area where an ecosystem has been disturbed, removed, or destroyed, and that contains soil or bottom sediment?

a. primary succession

b. secondary succession

c. ecological establishment

d. disturbance succession

e. facilitation

ANS:BPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Understand NOT: New

41.Which of the following exhibits secondary ecological succession?

a. abandoned parking lot

b. newly cooled lava

c. newly constructed reservoir

d. a crumbled concrete building

e. recently flooded land

ANS:EPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Apply

42.The situation in which one set of species makes an area suitable for species with different niche requirements and often, less suitable for itself, is called ____.

a. primary succession

b. secondary succession

c. facilitation

d. inhibition

e. tolerance

ANS:CPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Remember NOT: New

43.Late successional plants are largely unaffected by plants at earlier stages of succession because they are not in direct competition for resources, a factor called ____.

a. facilitation

b. imperturbability

c. inhibition

d. tolerance

e. intolerance

ANS:DPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Understand NOT: Modified

44.Most ecologists now recognize that mature, late-successional ecosystems ____.

a. are in a state of continual disturbance and change

b. are in a stable state of equilibrium

c. are in natural balance with their environment

d. have followed an expected path to their stable state as a climax community

e. have inevitably progressed through succession and no longer face competition

ANS:APTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Understand NOT: New

45.The capacity to withstand external stress and disturbance is called ____.

a. equilibrium

b. stability

c. balance of nature

d. facilitation

e. inhibition

ANS:BPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Understand NOT: New

46.The ability of a living system to survive moderate disturbances is called ____.

a. stability

b. inertia

c. constancy

d. tipping point

e. resilience

ANS:BPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Remember

47.What refers to the ability of a living system to be restored after a period of moderate to severe disturbance?

a. stability

b. inertia

c. constancy

d. tipping point

e. resilience

ANS:EPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Remember

48.If the resilience of a damaged ecosystem is low enough, the degraded area may not be restored by secondary succession. When this happens, the damaged ecosystem has reached ____.

a. stability

b. inertia

c. constancy

d. a tipping point

e. resilience

ANS:DPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Understand NOT: Modified

49.Grasslands have ____ and can burn easily.

a. low facilitation

b. high facilitation

c. low resilience

d. high inertia

e. low inertia

ANS:EPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Apply NOT: New

50.Which of the following exhibits primary succession?

a. a rock exposed by a retreating glacier

b. an abandoned farm

c. a clear-cut forest

d. newly flooded land

e. a recently burned forest

ANS:APTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Apply

TRUE/FALSE

1.The southern sea otter is a tool-using mammal.

ANS:TPTS:1

TOP: Figure 5-1 | 5-0 Core Case Study: The Southern Sea Otter: A Species in Recovery

KEY:Bloom’s: Understand

2.The most common interaction between species is commensalism.

ANS: F PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Understand

3.Humans compete with many other species for space, food, and other resources.

ANS: T PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Remember

4.Animal predators tend to kill the sick, weak, aged, and least fit members of a species because they are the easiest to catch.

ANS: T PTS: 1 TOP: 5-1 How Do Species Interact?

KEY: Bloom’s: Understand NOT: Modified

5.In predator-prey relationships, the predator is seeking food for itself and its offspring, while the prey is seeking not to become food for the predator. As a result, predator and prey populations exert tremendous natural selection pressures on each other.

ANS: T PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Apply

6.At the population level, parasites are always harmful to the host species.

ANS: F PTS: 1 TOP: 5-1 How Do Species Interact?

KEY:Bloom’s: Understand

7.Organisms with clumped distributions are fairly rare.

ANS: F PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Understand

8.Large mammals, such as elephants and rhinoceroses, are especially vulnerable to extinction because of their reproductive patterns.

ANS: T PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Understand NOT: Modified

9.The growth rate of a population increases as its size nears the carrying capacity of its environment.

ANS: F PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Analyze NOT: Modified

10.The carrying capacity of any given area is not fixed.

ANS: T PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Understand

11.Humans are exempt from population overshoot and dieback.

ANS: F PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Apply

12.Primary and secondary ecological succession tend to increase biodiversity of communities and ecosystems by increasing species richness and interactions among species.

ANS:TPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Understand NOT: Modified

13.Scientists have changed their view about a stable type of climax community as the end product of succession and are now suggesting we can not predict the course of succession.

ANS:TPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Analyze

14.Grasslands have a high resilience and therefore can recover quickly following a fire.

ANS:TPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Understand NOT: Modified

15.In communities and ecosystems the types and numbers of species change in response to changing environmental conditions.

ANS:TPTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Understand

COMPLETION

1.The southern sea otter has been classified as a(n) ____________________ species because in their absence, kelp forests would probably be destroyed.

ANS: keystone

PTS: 1 TOP: 5-0 Core Case Study: The Southern Sea Otter: A Species in Recovery

KEY: Bloom’s: Understand NOT: Modified

2.____________________ is a competitive interaction between species for food, water, light and/or space.

ANS: Interspecific competition

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Remember

NOT: Modified

3.When two or more species compete with one another their niches are said to ____________________.

ANS: overlap

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Understand

4.____________________ occurs when a member of one species feeds directly on all or part of a member of another species.

ANS: Predation

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Remember

5.Bad-tasting, bad-smelling, toxic, or stinging-prey species advertise their characteristics using ____________________.

ANS: warning coloration

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Understand

NOT: Modified

6.Some prey species make themselves larger or mimic a predator, both of which are called ____________________.

ANS: behavioral strategies

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Understand

NOT: Modified

7.When two different species interact over a long time, changes in the gene pool help both species to become more competitive or avoid competition.  This is called _______________,

ANS: coevolution

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Remember

8.In _______________, two species behave in ways that benefit both by providing each with needed resources.

ANS: mutualism

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Remember

9.Vast armies of ____________________ inhabit the digestive tracts of animals, such as humans, and help break down or digest their food.

ANS: bacteria

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Remember

10.The gradual change in species composition in a given area is called ____________________.

ANS: ecological succession

PTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Remember

11.The most common form of population dispersion found in nature is ____________________.

ANS: clumps

PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Remember

12.____________________ is the combination of all factors that act to limit the growth of a population.

ANS: Environmental resistance

PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Remember

13.A population exceeding its carrying capacity will suffer a(n) ____________________ or ____________________, unless the excess individuals can switch to new resources or move to a new area.

ANS:

dieback; crash

crash; dieback

PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY:Bloom’s: Apply

14.____________________ involves the gradual establishment of biotic communities in lifeless areas where there is no soil.

ANS: Primary succession

PTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Understand

15.One of the factors determining the rate of succession is _______________, in which one set of species makes an area suitable for other species with different requirements.

ANS: facilitation

PTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY:Bloom’s: Understand

SHORT ANSWER

1.Describe what happens when species partition resources.

ANS:

Resource partitioning occurs when species competing for similar scarce resources evolve specialized traits that allow them to share resources by using parts of them, using them at different times, or using them in different ways.

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Understand

NOT: New

2.What method of hunting prey do Arctic foxes use?

ANS:

Arctic foxes use camouflage by blending into their snowy background to avoid detection, and then they ambush their prey.

PTS:1TOP:Figure 5-5 | 5-1 How Do Species Interact?

KEY: Bloom’s: Apply NOT: New

Use the figure above to answer the following question(s).

3.Determine which portion of the accompanying graph represents the number of reindeer that can be sustained indefinitely in a given area. What term illustrates this?

ANS:

Letter A represents the carrying capacity.

PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Analyze NOT: New

4.What does it mean when a population uses up their resource supplies and temporarily overshoots?  Which letter on this graph represents when this has occurred to a certain reindeer population?

ANS:

The population exceeds the carrying capacity of their environment. It is represented by letter B.

PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Analyze NOT: New

5.What happens to a population if a dieback occurs, and which portion of the graph represents this?

ANS:

A population suffers a sharp decline, also called a population crash.  It is represented by letter C.

PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Analyze NOT: New

ESSAY

1.Explain why it is important to care about the survival of the endangered southern sea otters of California.

ANS:

One reason is for ethical reasons, as many people believe it is wrong to allow human activities to cause the extinction of a species. Another reason is that people love to watch this lovable and intelligent animals as they play in water, which results in millions of dollars a year in tourism revenues. Finally, biologists classify southern sea otters as keystone species, which means that in their absence sea urchins and other kelp-eating species on which sea otters feed would probably destroy the Pacific coast kelp forests and much of the biodiversity they support.

PTS: 1 TOP: 5-0 Core Case Study: The Southern Sea Otter: A Species in Recovery

KEY: Bloom’s: Analyze NOT: New

2.Using a small rodent, such as a field mouse, and a predator, such as a snake, explain how coevolution works.

ANS:

The rodent responds to the environmental pressure applied by the snake through changes in behavior, anatomy, or physiology to reduce the predation. The snake, facing reducing predatory success, changes in response to the rodent. The rodent again responds to the specifics of the environmental pressure. This step-by-step adaptation is known as coevolution.

PTS: 1 TOP: 5-1 How Do Species Interact? KEY: Bloom’s: Apply

3.At the present time the global human population surpasses seven billion people. If we exceed the carrying capacity of the earth, the human population may suffer a substantial collapse.

Consider the following formula for population change:

population change = (births + immigration)  (deaths + emigration)

What will be required of humans in order to stabilize or reduce our population?

ANS:

Speaking on a global scale, there is no place for us to come from (immigration) or go to (emigration). That means population change is limited to births minus deaths. To put it in the crudest of terms, we must either reduce the number of births or increase the number of deaths in order to stabilize or reduce our population. If we choose not to undertake that change, nature will do so as we exceed our carrying capacity.

PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Analyze NOT: Modified

4.Some people blame white-tailed deer for invading suburban yards and gardens.  Discuss potential solutions to this problem.

ANS:

There are no easy answers to the deer population problem in the suburbs.  Changes in hunting regulations that allow for the killing of more female deer have cut down the overall deer population.  However, since widespread hunting is not allowed in suburban areas, some areas have hired experienced archers to help reduce deer numbers safely.  Some communities spray the scent of deer predators or rotting deer meat on the edges of suburban areas to scare off deer.  Others have used equipment that emits high frequency sounds, which are undetectable to humans.  Some people surround their yards with high fences over which the deer can not jump.  In addition to these deterrents, deer can be trapped and moved, but this is expensive and must be repeated whenever the deer return.  People could try birth control for deer to keep their numbers down or they could try trapping dominant males and sterilizing them.

PTS: 1 TOP: 5-3 What Limits the Growth of Populations?

KEY: Bloom’s: Analyze NOT: New

5.Describe the three factors ecologists have identified that affect how and at what rate succession occurs.

ANS:

The first factor that affects how and at what rate succession occurs is facilitation.  This is when one set of species makes an area suitable for species with different niche requirements, and often less suitable for itself.  For example, lichens and mosses gradually build up soil on rocks in primary succession, which allows grasses and other plants to move in and crowd out the lichens and mosses.  The second factor is inhibition, in which some species hinder the establishment and growth of other species.  For example, needles dropping off some pine trees make the soil beneath the trees too acidic for most other plants to grow there.  The third factor is tolerance, whereby plants in the late stages of succession succeed because they are not in direct competition with other plants for key resources.  For example, shade-tolerant species can live in shady forests because they do not need as much sunlight as the trees above them do.

PTS:1

TOP: 5-2 How Do Communities and Ecosystems Respond to Changing Environmental Conditions?

KEY: Bloom’s: Analyze NOT: New