Ecology - Pt.1 of 2 for FINAL EXAM

Question 1

An ecologist conducts a study to answer the question: Are predator-prey interactions more important in
tropical forests than in temperate forests? At what level is the ecologist working?

(a) Landscape
(b) Ecosystem
(c) Community
(d) Population
(e) Organismal

Answer 1

(c) Community

Question 2

An ecologist wants to answer the question: Have tiger sharks been declining in the north Atlantic? At
what level is the ecologist working?

(a) Landscape
(b) Ecosystem
(c) Community
(d) Population
(e) Organismal

Answer 2

(d) Population

Question 3

The tropics receive a lot of precipitation because

(a) Rising warm air cools and releases moisture
(b) The rising warm air carries the moisture north and south
(c) Most of the tropics are close to warm oceans
(d) Mountains cause moisture to be released from the air

Answer 3

(a) Rising warm air cools and releases moisture

Question 4

Which is an example of how ocean currents influence land temperatures?

(a) The California current warms the western USA
(b) The Labrador current cools eastern Canada
(c) The Antarctic Circumpolar Current warms the southern tips of Africa and South America
(d) Western coasts of continents tend to be warmed by the major subtropical gyres while eastern coasts
tend to be cooled

Answer 4

(b) The Labrador current cools eastern Canada

Question 5

Which of the following best describes a link between climate and terrestrial biomes?

(a) Forested biomes are usually found in the tropics because it is warmer there
(b) Non-forested biomes are more common where the climate is drier
(c) Differences in climate matter more in biomes close to the equator
(d) Tropical rainforests occur in cooler climates than subtropical desert

Answer 5

(b) Non-forested biomes are more common where the climate is drier

Question 6

Temperate broadleaf forests

(a) tend to be drier than northern coniferous forests
(b) tend to be warmer than northern coniferous forests
(c) tend to be cooler than temperate grassland
(d) tend to be drier than temperate grasslands

Answer 6

(b) tend to be warmer than northern coniferous forests

Question 7

Which of the following terrestrial biomes is subject to frequent fires?

(a) savanna
(b) temperate forest
(c) tropical forest
(d) desert

Answer 7

(a) savanna

Question 8

Which of the following characteristics best distinguishes temperate grassland from tropical savannah?

(a) mean annual temperature
(b) mean annual precipitation
(c) maximum annual precipitation
(d) importance of disturbance

Answer 8

(a) mean annual temperature

Question 9

Which of the following describes the density of a population?

(a) Approximately 2000 grizzly bears live in Banff National Park
(b) There are 150 bighorn sheep for every cougar in Jasper National Park
(c) The number of pikas in Kluane National Park has declined by 20% over 3 years
(d) On average, there are five elk per square kilometre in the Ghost Wilderness Area

Answer 9

(d) On average, there are five elk per square kilometre in the Ghost Wilderness Area

Question 10

Alder trees tend to be found beside streams and rivers. Within a forest, the dispersion pattern of alder
is most likely to be

(a) dense
(b) clumped
(c) random
(d) uniform

Answer 10

(b) clumped

Question 11

The mark-recapture method would likely be most useful for estimating densities of

(a) phytoplankton
(b) annual plants
(c) perennial plants
(d) snowshoe hares

Answer 11

(d) snowshoe hares

Question 12

An ecologist wanted to determine the size of a population of lemmings on an island in northern Canada. He set 200 traps and caught 30 lemmings. He marked each with an ear tag and released them. A week later he reset the traps and caught 40 lemmings, 5 of which had tags. What would be his best
estimate of the total number of lemmings in the population?

(a) 150
(b) 200
(c) 240
(d) 600
(e) 1200

Answer 12

(c) 240

Question 13

A marine ecologist wanted to determine the size of a population of green crabs that had invaded a
coastal bay. She swam 10 transects across the bay, looking for green crabs. She found 50 and marked each
with a notch on its back and then released it. Three days later she swam 10 transects again. This time she
saw 80 crabs but only 2 had marks. What would be her best estimate of the total number of green crabs in
the population?

(a) 100
(b) 160
(c) 400
(d) 2000
(e) 4000

Answer 13

(d) 2000

Question 14

Populations are most likely to exhibit exponential growth

(a) under crowded conditions
(b) if the population growth rate (r) is very high
(c) as population size (N) increases
(d) if resources are not limiting
(e) if the body size is small

Answer 14

(d) if resources are not limiting

Question 15

Per capita birth rate was 0.25 and per capita death rate was 0.15 for a population of 1000 protozoa in
a laboratory flask. What is the per capita growth rate of the population?
(a) 250
(b) 150
(c) 100
(d) 0.10
(e) 0.40

Answer 15

(d) 0.10

Question 16

Twenty rats were introduced onto an island. Per capita birth rate was estimated to be 2.5 and per
capita mortality rate at 0.4. If the population grew exponentially, approximately how many rats were
present on the island after 5 generations? (requires calculator)

(a) 42
(b) 20,000
(c) 70,000
(d) 500,000
(e) more than 700,000

Answer 16

(e) more than 700,000

Question 17

A population of 50 poison dart frogs was discovered. The per capita birth rate was estimated to be 0.2
and the per capita death 0.3. What was the per capita rate of increase for the population?
(a) 10
(b) 5
(c) 0.10
(d) -0.10
(e) -0.50

Answer 17

(d) -0.10

Question 18

A hummingbird population of 50 individuals has per capita birth rate of 1.5 and a per capita death rate
of 2.0. What would the per capita mortality rate need to be for the population to show zero growth?
(a) 0
(b) 0.5
(c) 1.5
(d) 3.5

Answer 18

(c) 1.5

Question 19

Which does NOT contribute to population growth during locust outbreaks?
(a) females lay eggs near green vegetation
(b) rainfall
(c) high hopper survival rates
(d) increased parasitism

Answer 19

(d) increased parasitism

Question 20

Choose the statement that is CORRECT
(a) Desert locusts tend to have outbreaks at regular intervals (e.g. every 20 years)
(b) Outbreaks of desert locusts are typically associated with droughts
(c) Crowding causes morphological change in desert locusts
(d) Recent outbreaks of desert locusts are primarily due to global warming

Answer 20

(c) Crowding causes morphological change in desert locusts

Question 21

Gregarization in the desert locust involves
(a) lowered interspecific competition for food
(b) a change in behaviour such that individuals are attracted to each other
(c) reduced mobility
(d) increased carnivory

Answer 21

(b) a change in behaviour such that individuals are attracted to each other

Question 22

What induces gregarization in the desert locust?
(a) A moister environment (heavy rainfall) increases locust metabolic rates
(b) Consumption of green vegetation causes changes in pigmentation
(c) Physical contact with other locusts leads to hormonal changes
(d) Consumption of pesticides associated with field crops leads to changes in behaviour

Answer 22

(c) Physical contact with other locusts leads to hormonal changes

Question 23

How does dispersal influence locust outbreaks?
(a) Increased mobility tends to reduce per capita growth rate
(b) Increased mobility tends to increase the spatial extent of the plague but reduce its intensity
(c) Increased mobility tends to prolong the outbreak, as locusts find new sources of food
(d) Increased mobility causes locust number to drop

Answer 23

(c) Increased mobility tends to prolong the outbreak, as locusts find new sources of food

Question 24

Which is true for desert locust populations?
(a) Per capita rate of increase (r) varies with environmental conditions
(b) Per capita rate of increase (r) exceeds the carrying capacity of the environment
(c) Per capita rate of increase (r) decreases due to a clumped dispersion pattern of hoppers

Answer 24

(a) Per capita rate of increase (r) varies with environmental conditions

Question 25

An example of a density-independent factor would be:

a) Wolves kill a greater proportion of an elk population when elk are very abundant
b) A greater percentage of snowshoe hares die of malnutrition in the winter when densities are high
c) About 10% of chickadees freeze to death each winter
d) The offspring of sea otters have lower rates of survivorship as population size increases

Answer 25

c) About 10% of chickadees freeze to death each winter

Question 26

An example of density-dependent death rates would be:

a) Growth rates of crops such as wheat increase when fertilizers are used
b) Hormonal changes due to crowding cause mice to produce fewer offspring
c) Death rates due to the disease typhus are much higher in crowded cities than in rural areas
d) Population size of large predators such as cheetahs is often limited by territorial behaviour

Answer 26

c) Death rates due to the disease typhus are much higher in crowded cities than in rural areas

Question 27

Which of the following is NOT correct for the carrying capacity (K) of a population?
a) K is likely to fluctuate over time as the environment changes
b) K may be set by the number of available sheltering sites rather than the amount of food
c) K is likely to decrease as a population becomes more crowded
d) K is often determined by how many resources are available

Answer 27

c) K is likely to decrease as a population becomes more crowded

Question 28

In the logistic growth model, zero population growth is achieved when
a) r < 0
b) N = K
c) (K-N)/K > 0
d) N = r

Answer 28

b) N = K

Question 29

For a population growing logistically, with r = 0.5 per year and K = 100, what will dN/dt equal if
population size is 60?
a) 50
b) 12
c) 0.2
d) 0

Answer 29

b) 12

Question 30

For a population growing logistically, with r = 2.5 per year and K = 50, what will dN/dt equal if
population size is 50?
a) 125
b) 50
c) 25
d) 0

Answer 30

d) 0

Question 31

A population growing according to the logistic equation will decline in abundance if
a) K is very large
b) N > K
c) r < 1
d) there are more males than females in the population

Answer 31

b) N > K

Question 32

A population growing according to the logistic equation will increase in abundance if
a) N < K
b) N > K
c) r < 0
d) r >0

Answer 32

a) N < K

Question 33

Species tend to evolve different life history strategies
a) due to semelparity
b) if they don’t reproduce
c) when they are not subject to natural selection
d) if the environments they live in are very different

Answer 33

16

Question 34

A characteristic usually associated with an r-strategy is:
a) Individuals produce few offspring
b) Individuals tend to have long lifespans
c) Individuals usually mate for life
d) Individuals tend to have high reproductive rates

Answer 34

d) Individuals tend to have high reproductive rates

Question 35

A K-strategist
a) usually does well in disturbed environments
b) is often a good competitor
c) is usually capable of very high population growth rates
d) generally selects environments with a high carrying capacity

Answer 35

b) is often a good competitor

Question 36

Where would you expect to find K-selected species?
a) in a small stream that dries up when there is little rain
b) in a tropical rain forest
c) in fire-dominated ecosystems such as tropical savannah
d) in urban vegetable gardens

Answer 36

b) in a tropical rain forest

Question 37

A population that has a Type I survivorship curve
a) usually has very high infant mortality rates
b) is usually declining in abundance
c) usually has high per capita birth rates
d) is often a K-strategist

Answer 37

d) is often a K-strategist

Question 38

In a population with a Type II survivorship curve
a) all ages have roughly the same mortality rate
b) the young have high mortality and the old lower mortality
c) the old have high mortality and the young low mortality
d) the young and old have high mortality and mid-aged individuals have low mortality

Answer 38

a) all ages have roughly the same mortality rate

Question 39

Which of the following would be most likely to show a Type III survivorship curve?
a) a species with individuals that produce many young but do not provide any parental care
b) a species with individuals that provide extended parental care for its offspring
c) a species with individuals that delay reproduction until they are quite large
d) a species where most individuals have an extended period of reproduction

Answer 39

a) a species with individuals that produce many young but do not provide any parental care

Question 40

Which has NOT directly contributed to the decline in global population growth rate over the past 30 years?
a) declining fertility in most countries
b) availability of birth control
c) mortality due to major diseases such as AIDS
d) tendency for females to start reproduction at a younger age

Answer 40

d) tendency for females to start reproduction at a younger age

Question 41

Which would be LEAST likely to accurately predict carrying capacity for humans on earth?
a) fitting a logistic growth curve to historic population sizes
b) estimating the amount of food that could be produced on earth
c) assuming continued exponential growth
d) multiplying the “maximum possible density” of humans by the amount of habitable land

Answer 41

c) assuming continued exponential growth

Question 42

Total fertility rate is
a) the same as per capita birth rate
b) the number of births minus infant mortality
c) number of children per female over her lifespan
d) number of children needed for births to equal deaths

Answer 42

c) number of children per female over her lifespan

Question 43

Which of the following statements is correct?
a) Technology has altered the earth’s carrying capacity for the human population
b) Carrying capacity is largely independent of resource use
c) Ecological footprints are primarily due to unequal distribution of food resources
d) The global human population may stabilize even if birth rates continue to exceed death rates

Answer 43

a) Technology has altered the earth’s carrying capacity for the human population

Question 44

The main reason that the sea otter population grew exponentially after otters were re-introduced to
the coast of Vancouver Island was
a) temperatures were optimal
b) they were well - adapted to the local environment
c) food resources were abundant
d) adult survival was very high

Answer 44

c) food resources were abundant

Question 45

• 36. Growth of sea otter populations eventually slows, usually due to
      a) catastrophic events such as oil spills
      b) increases in predation rate
      c) high mortality of nursing mothers
      d) density-dependent mortality of pups

Answer 45

d) density-dependent mortality of pups

Question 46

Which aspect of the sea otter’s life history suggests that it might be considered a K-selected species?
a) exponential growth after re-introduction
b) near extinction due to the fur trade
c) extended period of parental care for offspring
d) density-dependent pup mortality

Answer 46

c) extended period of parental care for offspring

Question 47

Why did the populations of China continue to grow for a time, after it reached the replacement
fertility rate?
a) immigration
b) unequal sex ratio
c) there were many young individuals in the population
d) because the one child policy was unsuccessful

Answer 47

c) there were many young individuals in the population

Question 48

Where would most of the primary production occur in a large freshwater lake?
(a) profundal zone
(b) benthic zone
(c) photic zone
(d) oligotrophic zone
(e) aphotic zone

Answer 48

(c) photic zone

Question 49

Thermal stratification…[ans]
(a) occurs when a layer of warm, dense water overlies cooler, less dense water
(b) allows nutrients to sink to the bottom of the lake or ocean
(c) can prevent oxygen at the lake surface from mixing with deeper waters
(d) is linked to the transport of nutrients from warm equatorial regions to colder temperate
areas

Answer 49

(c) can prevent oxygen at the lake surface from mixing with deeper waters

Question 50

Most temperate lakes stratify in the summer and turn over in spring and fall. What is one consequence of the turnover?
(a) nutrients are carried from the lake bottom to the surface
(b) surface water tends to become oxygenated
(c) a thermocline is formed
(d) productivity in the benthic zone declines

Answer 50

(a) nutrients are carried from the lake bottom to the surface

Question 51

Oligotrophic lakes are lakes in which…
(a) there is little primary production, usually because nutrient levels are low
(b) thermoclines inhibit photosynthesis by phytoplankton
(c) the surface waters freeze in winter
(d) oxygen levels tend to be low

Answer 51

(a) there is little primary production, usually because nutrient levels are low

Question 52

Estuaries..?
(a) tend to have fluctuating salinity levels
(b) are exposed to the air when the tide recedes
(c) occur where smaller streams join to form rivers
(d) tend to be found in the ocean pelagic zone

Answer 52

(a) tend to have fluctuating salinity levels

Question 53

The neritic zone..
(a) is closely associated with coral reefs
(b) is part of the freshwater wetlands biome
(c) is the relatively shallow water over submerged continental shelves
(d) is found close to hydrothermal vents

Answer 53

(c) is the relatively shallow water over submerged continental shelves

Question 54

Interspecific competition is usually a..
(a) +/+ interaction
(b) +/- interaction
(c) -/- interaction
(d) -/0 interaction
(e) 0/0 interaction

Answer 54

(c) -/- interaction

Question 55

Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients and water from the vascular tissues of the trees. The trees derive no known benefits from the dwarf mistletoes, but also suffer no measurable cost from the association. Which of the following best describes the interactions between dwarf mistletoes and trees?
(a) mutualism
(b) parasitism
(c) commensalism
(d) facilitation
(e) competition

Answer 55

(c) commensalism

Question 56

Different species of Caribbean lizards search for food at different heights within a tree. This is an example of
(a) symbiosis
(b) species occupying different niches
(c) the competitive exclusion principle
(d) extinction due to logistic growth

Answer 56

(b) species occupying different niches

Question 57

The realized niche of the smaller barnacle, Chthamalus, is less than its fundamental niche because of
(a) interspecific competition
(b) intraspecific competition
(c) shortage of food
(d) predation by the seastar, Pisaster
(e) dessication when the tide is out

Answer 57

(a) interspecific competition

Question 58

Experimental removal of Chthamalus from the upper intertidal
(a) increased settlement by its competitor, Balanus
(b) increased intraspecific competition for Chthamaulus
(c) had no effect on survival of newly settled Balanus
(d) increased the level of interspecific competition in the lower intertidal

Answer 58

(c) had no effect on survival of newly settled Balanus

Question 59

What prevents Balanus from occupying the upper intertidal?
(a) insufficient food
(b) predation
(c) interspecific competition
(d) inability to survive long periods of time exposed to the air

Answer 59

(d) inability to survive long periods of time exposed to the air

Question 60

What prevents Chthamalus from occupying the lower intertidal?
(a) insufficient food
(b) predation
(c) interspecific competition
(d) inability to survive long periods of time exposed to the air

Answer 60

(c) interspecific competition

Question 61

Corals are invertebrates that..
(a) can photosynthesize
(b) have low species diversity because of their restricted geographical range
(c) occur primarily in the oceanic pelagic zone
(d) form external, carbonaceous skeletons

Answer 61

(d) form external, carbonaceous skeletons

Question 62

The benefit that corals derive from their symbiotic zooxanthellae is
(a) an enhanced supply of nitrogen
(b) protection from predators
(c) the products of photosynthesis
(d) calcium for their carbonaceous skeletons

Answer 62

c) the products of photosynthesis

Question 63

Coral bleaching occurs..
(a) because of a shortage of symbionts in the environment
(b) when zooxanthellae are expelled by the coral
(c) primarily as a response to nutrient addition
(d) due to a breakdown in the photosynthetic ability of the coral

Answer 63

(b) when zooxanthellae are expelled by the coral

Question 64

Macroalgae are more likely to “win” in competition with corals
(a) under low nutrient conditions
(b) on stable reefs with little physical disturbance
(c) where herbivore populations have been greatly reduced
(d) on reefs further from shore

Answer 64

(c) where herbivore populations have been greatly reduced

Question 65

The discharge of nutrient-rich sewage into tropical coastal habitats is likely to affect the outcome of competition between macroalgae and corals mostly through..
(a) effects on the growth rate of macroalgae
(b) effects on the death rate of macroalgae
(c) effects on the death rate of corals
(d) effects on growth rate of corals

Answer 65

(a) effects on the growth rate of macroalgae

Question 66

One of the factors that has contributed to the decline of corals on Caribbean reefs is
(a) increase in coral disease
(b) outbreaks of the sea urchin, Diadema
(c) increases in herbivorous fish
(d) establishment of no-take zones in the fishery

Answer 66

(a) increase in coral disease

Question 67

In the Caribbean, coral declines have occurred most strongly on reefs near islands that
(a) have experienced outbreaks of coral disease
(b) have a strong tourist industry
(c) have low abundances of herbivorous fish
(d) have experienced warmer than average temperatures

Answer 67

(c) have low abundances of herbivorous fish

Question 68

The transition of coral-dominated reefs to macroalgal-dominated reefs after the collapse of the sea urchin (Diadema) population in the Caribbean is an example of..
(a) the importance of predator-prey interactions on coral reefs
(b) the dependence of corals on symbiotic protists
(c) the vulnerability of corals to Diadema predation
(d) how competitive interactions can change if the environment changes

Answer 68

(d) how competitive interactions can change if the environment changes

Question 69

After disease led to the near elimination of Diadema from the Caribbean, corals survived
best on reefs where..
(a) parrotfish were still abundant
(b) coral diversity had been highest
(c) zooxanthellae were relatively healthy
(d) water temperatures were warmest

Answer 69

(a) parrotfish were still abundant

Question 70

Redundancy in ecological communities is
(a) found most often in aquatic biomes
(b) often caused by mortality due to humans (e.g., fishing)
(c) the presence of two or more species with similar ecological roles
(d) highest in the more vulnerable environments

Answer 70

(c) the presence of two or more species with similar ecological roles

Question 71

Snowshoe hares on Jacquot Island in the Yukon have greater total biomass than any other species in the food web. Hares would likely be
(a) a keystone species
(b) an ecological engineer
(c) a basal species
(d) a dominant species
(e) a keynote species

Answer 71

(d) a dominant species

Question 72

Kelp beds are present along the Pacific coast of North America..
(a) where killer whales reduce the densities of sea otters
(b) when sea otters reduce the densities of sea urchins
(c) when food chain length is four
(d) when sea otters were harvested almost to extinction

Answer 72

(b) when sea otters reduce the densities of sea urchins

Question 73

Fertilizer was added to the soil of a garden. The plants grew faster and reached larger sizes. Herbivorous insects became more abundant. This would be an example of..
(a) Top-down control
(b) Bottom-up control
(c) A trophic cascade
(d) A regime shift

Answer 73

(b) Bottom-up control

Question 74

After wolves were re-introduced to Yellowstone National Park in the 1990’s, elk, the wolves’ main prey, declined to less than half of its former abundance. This would be an example of..
(a) Top-down control
(b) Bottom-up control
(c) Disturbance influencing species richness
(d) A regime shift

Answer 74

(a) Top-down control

Question 75

The trophic cascade model is an example of…
(a) Top-down control
(b) Bottom-up control
(c) Disturbance influencing species richness
(d) Unstable communities

Answer 75

(a) Top-down control

Question 76

Which is one reason that sea otters are considered a keystone species on the Pacific coast?
(a) The biomass and species diversity of fish is higher in the presence of sea otters
(b) Sea otters are an alternative food for killer whales
(c) Primary productivity drops when sea otters are present
(d) Sea otters are K-selected organisms that provide extensive parental care to their young

Answer 76

(a) The biomass and species diversity of fish is higher in the presence of sea otters

Question 77

What allows kelp beds to be present in the coastal waters of Nova Scotia?
(a) It’s a bottom-up controlled community
(b) East coast kelp species are less susceptible to sea urchin grazing
(c) Disease occasionally decimates the sea urchin population, allowing the kelp to recover
(d) Lower species diversity on the east coast means that trophic cascades are less important

Answer 77

(c) Disease occasionally decimates the sea urchin population, allowing the kelp to recover

Question 78

A regime shift is…
(a) an increase in species richness
(b) rapid recovery after a disturbance
(c) a large and abrupt change to community structure that is persistent
(d) a type of community (e.g., tropical savannah) that depends on disturbance

Answer 78

(c) a large and abrupt change to community structure that is persistent

Question 79

Cold viruses have likely evolved the ability to make their hosts sneeze as a way of..
(a) increasing the likelihood of finding a new host
(b) ridding the body of a build-up of toxins
(c) escaping predators
(d) feeding more efficiently

Answer 79

(a) increasing the likelihood of finding a new host

Question 80

The life stage of a black-legged tick least likely to have the Lyme pathogen is..
(a) the larval stage
(b) the nymph stage
(c) the adult female
(d) the adult male

Answer 80

(a) the larval stage

Question 81

The preferred host of the adult black-legged tick is..
(a) migratory birds
(b) white-footed mice
(c) foxes
(d) deer

Answer 81

(d) deer

Question 82

Which of the following was the main driver of the increase in abundance of black-legged ticks in the northeastern USA during the first half of the 20th century?
(a) increase in the number of deer
(b) increase in the number of small mammals
(c) decline in migratory bird populations
(d) climate change

Answer 82

(a) increase in the number of deer

Question 83

What is thought to be the main role of climate change in the spread of Lyme disease in Canada?
(a) A warmer climate will alter forest vegetation so as to increase deer numbers
(b) A warmer climate will increase the likelihood of human-tick encounters by altering tick behaviour
(c) A warmer climate will allow populations of black-legged ticks to survive further north
(d) A warmer climate will shift the routes of migratory birds

Answer 83

(c) A warmer climate will allow populations of black-legged ticks to survive further north

Question 84

How might range expansion of the Eastern coyote have contributed to an increase in the incidence of Lyme disease?
(a) By reducing the abundance of deer populations
(b) By enhancing the likelihood of encounters between adults ticks and deer
(c) By changing human behaviour
(d) By reducing the abundance of smaller predators that exert top-down control on small mammals

Answer 84

(d) By reducing the abundance of smaller predators that exert top-down control on small mammals

Question 85

White-footed mice are more abundant in oak forests in years when the trees produce unusually high numbers of acorns. This is an example of:
(a) Top-down control
(b) Bottom-up control
(c) Trophic cascade
(d) Mutualism

Answer 85

(b) Bottom-up control

Question 86

Which of the following human behaviours is likely to increase the incidence of Lyme disease in
humans?
(a) Preference for hiking in higher elevation, non-forested ecosystems
(b) Intensive use of insecticides containing DEET
(c) Suburban housing developments embedded in forested areas
(d) Travel to tropical regions

Answer 86

(c) Suburban housing developments embedded in forested areas

Question 87

Connectivity among ecosystem components is measured as
(a) species diversity (richness and evenness)
(b) rates of energy flow and nutrient cycling
(c) rates of population growth
(d) number of species interactions such as competition and mutualism
(e) food web complexity

Answer 87

(b) rates of energy flow and nutrient cycling

Question 88

One difference between the movement of energy and nutrients in an ecosystem is
(a) Energy can be stored for periods of time but nutrients cannot
(b) Nutrients can be stored for periods of time but energy cannot
(c) Nutrients tend to be retained and recycled within an ecosystem while energy must be continually
replenished from outside
(d) Energy tends to be retained and recycled within an ecosystem while nutrients must be continually
replenished from outside

Answer 88

(c) Nutrients tend to be retained and recycled within an ecosystem while energy must be continually
replenished from outside

Question 89

Radiant energy captured by plants is stored
(a) mostly in the root system
(b) mostly above ground
(c) in the molecular bonds of organic matter
(d) nowhere - energy cannot be stored

Answer 89

(c) in the molecular bonds of organic matter

Question 90

When energy is transformed from one form to another or moved from one component to another,
some energy is always lost in the form of heat. The ecosystem process associated with this loss of heat
energy is
(a) photosynthesis
(b) consumption
(c) death of organisms
(d) respiration

Answer 90

(d) respiration

Question 91

Which of the following are NOT autotrophs?
(a) phytoplankton
(b) kelp
(c) grasses
(d) barnacles

Answer 91

(d) barnacles

Question 92

During decomposition
(a) organic matter is converted to inorganic nutrients
(b) inorganic nutrients are converted to organic matter
(c) the net energy present in an ecosystem increases
(d) ecosystem biomass increases

Answer 92

(a) organic matter is converted to inorganic nutrients

Question 93

In most ecosystems, the majority of primary producers fix energy through
(a) photosynthesis
(b) chemosynthesis
(c) decomposition
(d) heterotrophy

Answer 93

(a) photosynthesis

Question 94

Which of the following would NOT be a measure of ecosystem function?
(a) rate of conversion of forest to cropland
(b) rate that new grass biomass is produced in a savannah ecosystem
(c) rate that zooplankton biomass is converted into herring biomass
(d) rate that leaves decompose in a small stream

Answer 94

(a) rate of conversion of forest to cropland

Question 95

An ecologist was studying restoration of a temperate grassland ecosystem. She found that, as the species composition of the grasses changed over time, the grazing bison began to gain weight at a faster rate. What would be a valid conclusion to draw from this observation?
(a) Primary production was likely declining
(b) Bison were likely experiencing less interspecific competition
(c) The bison herd was increasing in abundance
(d)The species composition of primary producers was influencing ecosystem function

Answer 95

(d)The species composition of primary producers was influencing ecosystem function

Question 96

Net primary production (NPP) is a measure of how much energy
(a) is captured by primary producers over a period of time
(b) is accumulated as primary producer biomass over a period of time
(c) is accumulated by an ecosystem over a period of time
(d) is lost due to respiration by primary producers over a period of time
(e) is lost due to respiration by an ecosystem over a period of time

Answer 96

(b) is accumulated as primary producer biomass over a period of time

Question 97

Net ecosystem production (NEP) is always negative if
(a) Ra > GPP
(b) Ra < GPP
(c) RT < NPP
(d) RT < GPP

Answer 97

(a) Ra > GPP

Question 98

Eutrophication (high rates of primary productivity in an aquatic community) usually occurs as a
result of
(a) high zooplankton death rates
(b) excessive nutrients in coastal waters
(c) high rates of denitrification
(d) high input of nutrients

Answer 98

(d) high input of nutrients

Question 99

Aquatic primary productivity is unlikely to be limited by
(a) nitrogen
(b) carbon
(c) nutrients
(d) light

Answer 99

(b) carbon

Question 100

Marine primary productivity is most likely to be high
(a) in tropical and subtropical gyres
(b) in areas of nutrient upwelling
(c) where temperatures are warmest
(d) under the Arctic ice

Answer 100

(b) in areas of nutrient upwelling

Question 101

Addition of nutrients to aquatic ecosystems often stimulates primary production, causing the
water to become turbid due to high densities of phytoplankton. This process is known as
(a) net ecosystem production
(b) trophic efficiency
(c) eutrophication
(d) decomposition

Answer 101

(c) eutrophication

Question 102

Dead zones in coastal ecosystems
(a) are caused by release of toxic chemicals into the environment
(b) occur when decomposition results in low oxygen levels at depth
(c) are the end result of the loss of top predators in the ecosystem
(d) are found floating near the water’s surface, often resulting in fish kills

Answer 102

(b) occur when decomposition results in low oxygen levels at depth

Question 103

Which of the following is an important physical reservoir for the terrestrial nitrogen cycle?
(a) soil water
(b) dead organic matter
(c) decomposers
(d) streams and lakes

Answer 103

(a) soil water

Question 104

Radiant energy is captured by plants and stored as
(a) heat energy
(b) chemical energy
(c) physical energy
(d) biological energy

Answer 104

(b) chemical energy

Question 105

Inorganic nutrients are taken up by primary producers and
(a) converted to chemical energy
(b) converted to radiant energy
(c) used to build inorganic matter
(d) used to build organic matter

Answer 105

(d) used to build organic matter

Question 106

Nitrates (NO3-) ions dissolved in the soil water of a garden would be
(a) inorganic molecules converted to ammonium ions by nitrifying bacteria
(b) inorganic molecules used as nitrogen source by N-fixing bacteria
(c) inorganic molecules used as a nitrogen source by plants

Answer 106

(c) inorganic molecules used as a nitrogen source by plants

Question 107

N2 molecules in the atmosphere are..
(a) inorganic molecules released from detritus during decomposition
(b) inorganic molecules used as a nitrogen source by plants
(c) inorganic molecules used as nitrogen source by N-fixing bacteria

Answer 107

(c) inorganic molecules used as nitrogen source by N-fixing bacteria

Question 108

Nitrogen fixation is the transformation of
(a) nitrogen gas to ammonium
(b) ammonium to nitrate
(c) organic nitrogen to ammonium
(d) nitrate to nitrogen gas

Answer 108

(a) nitrogen gas to ammonium

Question 109

Secondary consumers obtain their nitrogen in the form of
(a) nitrate ions
(b) nitrogen gas
(c) nitrous oxide
(d) organic molecules (organic matter)

Answer 109

(d) organic molecules (organic matter)

Question 110

In the nitrogen cycle, the bacteria that replenish the atmosphere with nitrogen gas are
(a) Rhizobium bacteria
(b) nitrifying bacteria
(c) denitrifying bacteria
(d) methanogenic protozoans
(e) nitrogen-fixing bacteria

Answer 110

(c) denitrifying bacteria

Question 111

Legumes add nitrogen to the soil
(a) through the process of nitrification
(b) through the process of assimilation
(c) through a symbiotic relationship with photosynthesizing algae
(d) through a symbiotic relationship with dentrifying bacteria
(e) through a symbiotic relationship with nitrogen-fixing bacteria

Answer 111

(e) through a symbiotic relationship with nitrogen-fixing bacteria

Question 112

Decomposition involves the transformation of
(a) nitrates to organic nitrogen
(b) organic nitrogen in living organisms to detritus
(c) organic nitrogen in detritus to ammonium ions
(d) nitrates to nitrogen gas
(e) nitrogen gas to ammonium

Answer 112

(c) organic nitrogen in detritus to ammonium ions

Question 113

The process of denitrification produces
(a) ammonia
(b) ammonium ions
(c) nitrates
(d) organic nitrogen
(e) nitrogen gas

Answer 113

(e) nitrogen gas

Question 114

The dead zone where the Mississippi River empties into the Gulf of Mexico is caused by
(a) low oxygen levels, as oxygen is depleted during decomposition of algae
(b) low nutrient levels, as photosynthesizing algae use up available nutrients
(c) low nitrogen levels, which limit coastal primary productivity
(d) warm temperatures which cause excessive algal growth

Answer 114

(a) low oxygen levels, as oxygen is depleted during decomposition of algae

Question 115

Burning fossil fuels..
(a) increases input of nitrogen to the atmosphere
(b) interferes with the action of denitrifying bacteria
(c) decreases atmospheric N2
(d) increases the rate of nitrification in the soil

Answer 115

(a) increases input of nitrogen to the atmosphere

Question 116

Nitrogen deposition..
(a) can increase primary production
(b) increases the activity of N-fixing bacteria
(c) leads to depletion of atmospheric N2
(d) decreases rates of decomposition

Answer 116

(a) can increase primary production

Question 117

The manufacture of commercial fertilizer (ammonium nitrate) involves the transformation of…
(a) N2 to NH4+ and NO3-
(b) NH3 to NO3-
(c) NO3- to NH4+
(d) NO3- to N2

Answer 117

(a) N2 to NH4+ and NO3-

Question 118

Excessive amounts of nitrate in the soil can..
(a) reduce availability of nitrogen to plants
(b) cause loss of soil cations (e.g. Ca2+) through leaching
(c) cause increases in the activity of nitrogen-fixing bacteria
(d) interfere with plant assimilation

Answer 118

(b) cause loss of soil cations (e.g. Ca2+) through leaching

Question 119

One measure of ecosystem function would be
(a) rate of primary production
(b) species richness
(c) number of secondary consumers
(d) an increase in radiant energy

Answer 119

(a) rate of primary production

Question 120

The manufacture of commercial fertilizers and their application to crops results in large increases in the rate that nitrogen flows
(a) from fossil fuels to the soil water
(b) from legumes to the soil water
(c) from the atmosphere to the soil water
(d) from primary producers to the soil water

Answer 120

(c) from the atmosphere to the soil water

Question 121

The largest human-related increases in nitrogen inputs to terrestrial ecosystems have been due to
(a) increased land area devoted to legume crops such as soybeans
(b) burning fossil fuels
(c) the oil and gas industry
(d) manufacture and use of commercial fertilizers

Answer 121

(d) manufacture and use of commercial fertilizers

Question 122

Rheas are large ostrich-like birds that live in South America. The male rhea constructs a nest, and mates with a female that lays some eggs in his nest. The male incubates the eggs and cares for the chicks after they hatch. Each female mates with and lays eggs in the nests of several males. This type of
mating system is known as..
(a) promiscuous
(b) monogamous
(c) polygynous
(d) polyandrous

Answer 122

(d) polyandrous

Question 123

In polygynous mating systems
(a) males and females are usually similar in size
(b) males are usually larger than females
(c) females are usually larger than males
(d) females start out smaller than males but end up larger

Answer 123

(b) males are usually larger than females

Question 124

What is an important environment condition for the evolution of polygamy?
(a) Mate guarding
(b) Females choose mates
(c) Females have a larger body size than males
(d) There is sufficient food for one parent to rear the offspring

Answer 124

(d) There is sufficient food for one parent to rear the offspring

Question 125

An altruistic behaviour is one..
(a) that reduces an individual’s fitness while increasing the fitness of another individual
(b) that increases an individual’s fitness while increasing the fitness of another individual
(c) that increases an individual’s fitness while reducing the fitness of another individual
(d) that reduces an individual’s fitness while reducing the fitness of another individual

Answer 125

(a) that reduces an individual’s fitness while increasing the fitness of another individual

Question 126

An example of altruistic behaviour in naked mole rat colonies would be
(a) one female producing all the offspring
(b) excavating a long tunnel to find food underground
(c) aggressive behaviour by the female queen to prevent other females from mating
(d) a worker mole rat defending the colony against a predator

Answer 126

(d) a worker mole rat defending the colony against a predator

Question 127

Spiteful behaviour is likely rare because
(a) selfishness is not an evolutionarily stable strategy
(b) it results in a cost to oneself while benefitting others
(c) it results in benefits for oneself while harming relatives
(d) it reduces one’s own fitness without aiding others (including relatives)

Answer 127

(d) it reduces one’s own fitness without aiding others (including relatives)

Question 128

The presence of altruistic behaviour in animals is usually due to kin selection, a theory maintaining
that..
(a) aggression between sexes promotes the survival of the fittest
(b) organisms may increase the number of copies of their genes transmitted to future generations by
assisting others who share those genes
(c) companionship is advantageous to animals because in the future they can help each other
(d) natural selection has generally favoured the evolution of exaggerated aggressive and submissive
behaviours to resolve conflict without grave harm to participants

Answer 128

(b) organisms may increase the number of copies of their genes transmitted to future generations by assisting others who share those genes

Question 129

Hamilton’s Rule states that, for a particular behaviour to be maintained by natural selection..
(a) the cost of a behaviour must be greater than its benefit
(b) the benefit to the recipient, weighted by the proportion of shared genes between actor and
recipient, must be greater than the cost to the actor
(c) the benefit to the actor must be greater than the cost to the recipient
(d) the benefit to the actor, weighted by the proportion of shared genes, must be greater than the costs to the recipient

Answer 129

(b) the benefit to the recipient, weighted by the proportion of shared genes between actor and recipient, must be greater than the cost to the actor

Question 130

The relatedness of a girl to her great-grandfather is
(a) 1/32
(b) 1/16
(c) 1/8
(d) 1/4
(e) 1/2

Answer 130

(c) 1/8

Question 131

The relatedness of a brother to his half sister (same father, different mothers) is:
(a) 1/32
(b) 1/16
(c) 1/8
(d) 1/4
(e) 1/2

Answer 131

(d) 1/4

Question 132

A brother runs into a building to save his sister (full sibling). He has a 40% chance of dying in the attempt. If they survive, the brother and sister will each have 2 children in the future. According to Hamilton’s Rule, (evolutionarily speaking) should he have tried to save his sister?
(a) Yes
(b) No

Answer 132

(a) Yes

Question 133

Suppose that the sister is a half-sister (they share a mother but not a father). Should he have tried to save her, according to Hamilton’s Rule?
(a) Yes
(b) No

Answer 133

(b) No

Question 134

Suppose that a man sees that his niece is in danger of drowning. The man is likely to produce 1 more child, and the niece will produce 3 children if she survives. How great can the man’s risk of dying be for the inclusive benefit to be greater than the cost, according to Hamilton’s rule?
(a) 20%
(b) 30%
(c) 50%
(d) 75%
(e) 80%

Answer 134

(d) 75%

Question 135

A skier sees that one of his first cousins is standing in an avalanche path and must decide whether to ski closer to warn them. The skier and his cousin would each produce 3 children if they survive. How great can the skier’s risk of dying be for the inclusive benefit to be greater than the cost, according to
Hamilton’s rule?
(a) < 10%
(b) < 25%
(c) < 50%
(d) < 75%
(e) < 80%

Answer 135

(b) < 25%

Question 136

An example of reciprocal altruism is..

(a) female Belding’s ground squirrels give alarm calls because many relatives live near by
(b) a mother is more likely to rescue her daughter than vice-versa
(c) a chimpanzee may groom an unrelated chimpanzee if the favour is likely to be returned later
(d) altruism is most common in small groups of closely related individuals

Answer 136

(c) a chimpanzee may groom an unrelated chimpanzee if the favour is likely to be returned later

Question 137

Why do young male Florida scrub jays stay to help their parents care for younger siblings more frequently than do their sisters?
(a) Male scrub jays mature more slowly than do females
(b) Males derive a higher inclusive fitness from helping due to higher relatedness
(c) Reproductive rates are higher for females
(d) Males add more to their inclusive fitness by staying, as staying improves their chances of eventually
obtaining a breeding territory

Answer 137

(d) Males add more to their inclusive fitness by staying, as staying improves their chances of eventually obtaining a breeding territory

Question 138

A factor that likely contributed to the evolution of eusociality in the naked mole rat is
(a) a highly disturbed habitat
(b) low reproductive rate
(c) unusually high genetic relatedness
(d) an environment that makes it difficult for an individual pair to successfully reproduce on their own

Answer 138

(d) an environment that makes it difficult for an individual pair to successfully reproduce on their own

Question 139

Staying to help rear younger sibling increases the inclusive fitness of young red wolves through..
(a) Kin selection and higher individual fitness
(b) Kin selection only
(c) Higher individual fitness only
(d) Lower individual fitness and no kin selection

Answer 139

(a) Kin selection and higher individual fitness

Question 140

Worker mole rats gain inclusive fitness through
(a) Kin selection and higher individual fitness
(b) Kin selection only
(c) Higher individual fitness only
(d) Lower individual fitness and no kin selection

Answer 140

(b) Kin selection only

Question 141

An example of how the environment may affect the evolution of social organization would be..
(a) army ants have soldiers to defend the colony
(b) only one to a few individuals reproduce in a eusocial society
(c) reproductively mature scrub jays help rear younger siblings in Florida where habitat is limited but
not in California where habitat is more abundant
(d) r-selected species tend to produce smaller offspring

Answer 141

(c) reproductively mature scrub jays help rear younger siblings in Florida where habitat is limited but
not in California where habitat is more abundant

Question 142

Which of the following is a global (international) environmental organization?
(a) SARA
(b) IUCN
(c) COSEWIC
(d) EPA

Answer 142

(b) IUCN

Question 143

According to COSEWIC, the difference between an endangered species and a threatened one is
(a) an endangered species is closer to extirpation
(b) a threatened species is closer to extinction
(c) threatened species are endangered outside Canadian borders
(d) endangered species are more likely to respond to recovery plans

Answer 143

(a) an endangered species is closer to extirpation

Question 144

A species is considered extirpated by COSEWIC if..
(a) it is now globally extinct but was never found in Canada
(b) it has recently been expanding its range outside of Canada
(c) it is no longer found in Canada but is still present elsewhere
(d) it is close to going extinct in Canada

Answer 144

(c) it is no longer found in Canada but is still present elsewhere

Question 145

Populations of American shad (a fish) spawn in rivers from Nova Scotia to the southern USA. Different populations have been found to be adapted to different temperature regimes. This is
most likely an example of
(a) genetic diversity
(b) species diversity
(c) community diversity
(d) ecosystem diversity

Answer 145

(a) genetic diversity

Question 146

Which of the following would NOT qualify as an ecosystem service?
(a) warm temperatures leading to evaporation
(b) blowfly larvae infesting a deer carcass
(c) bees pollinating an apple tree
(d) leaves decomposing on a forest floor

Answer 146

(a) warm temperatures leading to evaporation

Question 147

One aspect of the biodiversity crisis is the potential loss of whole ecosystems, e.g., wetlands. The most serious consequence of a loss of an ecosystem is likely to be..
(a) an increase in global warming and thinning of the ozone layer
(b) loss of ecosystem services on which people and other organisms depend
(c) increased fragmentation of habitat
(d) an increase in nitrogen deposition

Answer 147

(b) loss of ecosystem services on which people and other organisms depend

Question 148

Assume that the population dynamics of a fish population can be described by the logistic
equation..
dN/dt = rN (K - N)/K, r = (b - d)

Overharvesting would increase the risk of extinction primarily through effects on which variable?
(a) b
(b) d
(c) K
(d) N

Answer 148

(b) d

Question 149

Minimum viable population size..
(a) is the number of individuals that can be sustained by the environment
(b) is population size taking into account the number of breeding males and females
(c) is the smallest size that a population can be, and still have a high probability of persistence
(d) is the average size of a population, taking into account year to year variation

Answer 149

(c) is the smallest size that a population can be, and still have a high probability of persistence

Question 150

A population of salamanders living in a maple forest needs to have at least 75 adults to have a 95% probability of persisting for 100 years. The population currently has 100 adult
individuals. Which of the following conclusions can you draw from this information?
(a) The population is likely to go extinct within 100 years.
(b) The population is likely to decline to 75 adults within the next 100 years
(c) There is less than a 5% chance that the population will go extinct in the next 100 years
(d) There is more than a 5% chance that the population will go extinct in the next 100 years

Answer 150

(c) There is less than a 5% chance that the population will go extinct in the next 100 years

Question 151

Ecologists studying two species of turtle in a national park wanted to determine the MVP for each population (size with a 99% probability of surviving for 50 years). Minimum viable population size was 100 for painted turtles and 30 for snapping turtles. The park has 70 painted
turtles and 50 snapping turtles.

MVP painted turtles: 100
Painted turtle population size: 70
MVP snapping turtles: 30
Snapping turtle population size: 50

Which of the following conclusions is correct?
(a) Both populations have a 1% chance of surviving for 50 years
(b) The painted turtle population is less likely than the snapping turtle population to survive for the next 50 years
(c) The painted turtle population is more likely than the snapping turtle population to survive
for the next 50 years
(d) Neither population will survive 50 years

Answer 151

(b) The painted turtle population is less likely than the snapping turtle population to survive for the next 50 years

Question 152

Two populations of sandhill cranes were studied, each with 500 adult birds. MVP (95% probability of persisting 100 years) for the population nesting in a national park was
estimated to be 500 birds. MVP for the population nesting in mixed wetland/agricultural habitat
was 1000 birds.

1. Which population is more likely to survive for 100 years?
   (a) The population in the national park
   (b) The population in the mixed wetland/agricultural habitat
   (c) Both are equally likely to survive
2. Why might MVP be lower in the park?
   (a) Carrying capacity might be higher
   (b) Predation rates might be lower
   (c) Population size might vary less from year to year
   (d) Migration rates might be lower

Answer 152

1. (a) The population in the national park
2. (c) Population size might vary less from year to year

Question 153

What can cause Ne (effective population size) to be lower than the actual number of individuals in the population (N)?
(a) More males than females in the population
(b) Inadequate food resources
(c) High birth rates
(d) A small carrying capacity (K)

Answer 153

(a) More males than females in the population