Question 1

Why might a minimum viable population not be an ecologically effective population?

Accepted Answer

A population that is in a minimum viable-population state basically has the smallest number of individuals that would allow a population to survive, persist, and grow. It may not, however, have enough individuals to perform the ecosystem services that the population would normally provide. For example, let's say you had a barn full of mice that were eating your supply of grain. If you had two cats (of opposite sex), they would likely be a minimum viable population, as in they would be able to reproduce and grow their numbers, but they might not be effective at getting rid of all the mice in the barn. If you had a larger population of cats, it would be more likely that they would be able to keep the population of mice under control.

Question 2

Several decades ago, around 24 rabbits were introduced into the wild of Australia, a country with no native rabbit population, mild winters, and large rabbit-friendly food supplies. Where do you think the rabbit population is today, and was it a big deal that only 24 rabbits were released?

Accepted Answer

Due to a combination of factors such as the high fecundity of rabbits, large suitable habitats, long reproductive seasons (due to mild winters), and large and stable food supplies, the exponential growth of the rabbit population in Australia has been one of the most rapid expansions of a mammal ever documented in modern times. Even though the population only began with 24 individuals, through exponential growth, the population of rabbits today is over 200 million, which causes a plethora of damaging issues for almost all of Australia's ecosystems.

Question 3

Germany currently has a negative growth rate for people. Which of the following statements is true about this population?

Accepted Answer

A)  birth rate > death rate 
B)  death rate > birth rate 
C)  birth rate = death rate 
D)  Choices A and C could be true. 
E)  None of the above is true. 
A)  birth rate > death rate 
B)  death rate > birth rate 
C)  birth rate = death rate 
D)  Choices A and C could be true. 
E)  None of the above is true. B

Question 4

-A farm field becomes abandoned and milkweed plants grow up in numbers over time. Based on the shape of the graph below, what kind of growth is this population experiencing? Where is the population in its growth, and what does this mean?

Accepted Answer

Based on the graph above, it appears tha

Question 5

What would happen to a large moose population if wolves were removed from the ecosystem? Explain your answer in terms of density-dependent or density-independent factors.

Accepted Answer

Wolves are the natural predator of moose

Question 6

Which of the following influences population size?

Accepted Answer

A)  access to food 
B)  presence of predators 
C)  sufficient habitat 
D)  presence of pathogens 
E)  all of the above 
A)  access to food 
B)  presence of predators 
C)  sufficient habitat 
D)  presence of pathogens 
E)  all of the above

Question 7

How does maintaining the top-down regulation by wolves help in providing for diverse fish and amphibian communities in Yellowstone?

Accepted Answer

Wolf populations keep elk numbers in che

Question 8

Why is it ultimately better for a population to have some resistance factors (i.e., factors that reduce a population's size)?

Accepted Answer

There are many drawbacks for a populatio

Question 9

Lions in a savanna will increase in population as the total population of their prey species in the ecosystem increases. The number of lions present in the ecosystem is _____________.

Accepted Answer

A)  a density-independent factor 
B)  a reproductive strategy 
C)  a density-dependent factor 
D)  the biotic potential 
E)  at carrying capacity 
A)  a density-independent factor 
B)  a reproductive strategy 
C)  a density-dependent factor 
D)  the biotic potential 
E)  at carrying capacity

Question 10

If a population size is determined by food availability and not predation pressures, it is likely under which regulation type?

Accepted Answer

A)  top-down regulation 
B)  bottom-up regulation 
C)  global warming 
D)  boom-and-bust regulation 
E)  keystone species pressure 
A)  top-down regulation 
B)  bottom-up regulation 
C)  global warming 
D)  boom-and-bust regulation 
E)  keystone species pressure

Question 11

The number-one reason for the endangered status of many species is _____________.

Accepted Answer

A)  disease 
B)  habitat destruction 
C)  storms and floods 
D)  volcanic activity 
E)  None of the above is correct. 
A)  disease 
B)  habitat destruction 
C)  storms and floods 
D)  volcanic activity 
E)  None of the above is correct.

Question 12

Why is weather considered to be a density-independent factor?

Accepted Answer

Weather is a density-independent factor

Question 13

During a typical predator-prey population cycle, the increase in the predator population is normally seen _____________ an increase in the prey population.

Accepted Answer

A)  after 
B)  before 
C)  at the same time as 
D)  as not correlated with 
E)  as randomly changing with 
A)  after 
B)  before 
C)  at the same time as 
D)  as not correlated with 
E)  as randomly changing with

Question 14

Draw a graph of population size over time for wolves and elk in Yellowstone National Park. (Hint: think about the predator-prey relationship between the two species.)

Accepted Answer

Your graph should reflect a bo

Question 15

Subtracting the death rate from the birth rate gives the _____________.

Accepted Answer

A)  biotic potential 
B)  carrying capacity 
C)  logistic growth 
D)  population growth rate 
E)  exponential growth 
A)  biotic potential 
B)  carrying capacity 
C)  logistic growth 
D)  population growth rate 
E)  exponential growth

Question 16

Bighorn sheep were introduced to an island in the Gulf of California in 2010. Originally, 75 bighorns were introduced. When a census was taken in 2011, there were 100 bighorns found. What is the growth rate of the bighorns on the island?

Accepted Answer

A)  33% 
B)  3% 
C)  25% 
D)  4% 
E)  10% 
A)  33% 
B)  3% 
C)  25% 
D)  4% 
E)  10%

Question 17

A population at low density is more likely to _____________.

Accepted Answer

A)  undergo high intraspecific competition 
B)  lose genetic variability 
C)  be randomly distributed 
D)  show rapid rates of disease spread 
E)  adapt to environmental changes 
A)  undergo high intraspecific competition 
B)  lose genetic variability 
C)  be randomly distributed 
D)  show rapid rates of disease spread 
E)  adapt to environmental changes

Question 18

Which of the following terms best describes the spacing density of humans in relation to the biosphere?

Accepted Answer

A)  clumped distribution 
B)  random distribution 
C)  uniform distribution 
D)  r-adapted 
E)  none of the above 
A)  clumped distribution 
B)  random distribution 
C)  uniform distribution 
D)  r-adapted 
E)  none of the above

Question 19

Which of the following is NOT a characteristic of r-selected species?

Accepted Answer

A)  long life 
B)  early maturity 
C)  rapid growth of an individual 
D)  many, small offspring 
E)  niche generalists 
A)  long life 
B)  early maturity 
C)  rapid growth of an individual 
D)  many, small offspring 
E)  niche generalists

Question 20

What are some biological characteristics of a species that determines their life-history strategy?

Accepted Answer

A)  maturity rate 
B)  life span 
C)  level of fecundity 
D)  all the above 
E)  none of the above 
A)  maturity rate 
B)  life span 
C)  level of fecundity 
D)  all the above 
E)  none of the above

Exam 9: Population Ecology- the Wolf Watchers: Endangered Gray Wolves Return to the American West

Why might a minimum viable population not be an ecologically effective population?

Several decades ago, around 24 rabbits were introduced into the wild of Australia, a country with no native rabbit population, mild winters, and large rabbit-friendly food supplies. Where do you think the rabbit population is today, and was it a big deal that only 24 rabbits were released?

Germany currently has a negative growth rate for people. Which of the following statements is true about this population?

-A farm field becomes abandoned and milkweed plants grow up in numbers over time. Based on the shape of the graph below, what kind of growth is this population experiencing? Where is the population in its growth, and what does this mean?

What would happen to a large moose population if wolves were removed from the ecosystem? Explain your answer in terms of density-dependent or density-independent factors.

Which of the following influences population size?

How does maintaining the top-down regulation by wolves help in providing for diverse fish and amphibian communities in Yellowstone?

Why is it ultimately better for a population to have some resistance factors (i.e., factors that reduce a population's size)?

Lions in a savanna will increase in population as the total population of their prey species in the ecosystem increases. The number of lions present in the ecosystem is _____________.

If a population size is determined by food availability and not predation pressures, it is likely under which regulation type?

The number-one reason for the endangered status of many species is _____________.

Why is weather considered to be a density-independent factor?

During a typical predator-prey population cycle, the increase in the predator population is normally seen _____________ an increase in the prey population.

Draw a graph of population size over time for wolves and elk in Yellowstone National Park. (Hint: think about the predator-prey relationship between the two species.)

Subtracting the death rate from the birth rate gives the _____________.

Bighorn sheep were introduced to an island in the Gulf of California in 2010. Originally, 75 bighorns were introduced. When a census was taken in 2011, there were 100 bighorns found. What is the growth rate of the bighorns on the island?

A population at low density is more likely to _____________.

Which of the following terms best describes the spacing density of humans in relation to the biosphere?

Which of the following is NOT a characteristic of r-selected species?

What are some biological characteristics of a species that determines their life-history strategy?

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