Question 1

Which of the following consists of organisms, all of which share a common gene pool?
A) A community
B) A population
C) A biosphere
D) An ecosystem
E) A landscape

Accepted Answer

A population is a group of organisms of the same species that live in the same area and share a common gene pool.

Question 2

Which of the following is NOT a condition that is likely to lead to uniform population dispersion?
A) Nesting territoriality
B) Severe competition among individuals
C) Plant roots or shed leaves that produce toxic substances
D) Establishment of feeding or mating territories
E) Pressure from predation

Accepted Answer

Uniform dispersion is often a result of direct interactions between individuals within a population, such as competition for resources or the establishment of territories. Predation pressure, however, tends to lead to clumped dispersion as individuals group together for protection, rather than uniform dispersion.

Question 3

When r = −0.00057, the population size:
A) will increase.
B) will decrease.
C) is stable.
D) may increase or decrease, depending on K .
E) may increase or decrease, depending on i .

Accepted Answer

When r (the intrinsic rate of natural increase) is negative, it indicates that the population size will decrease.

Question 4

What is perhaps the most common of the dispersal patterns seen in nature?
A) Random dispersion
B) Disaggregated dispersion
C) Uniform dispersion
D) Density-dependent distribution
E) Clumped dispersion

Accepted Answer

Clumped dispersion is the most common dispersal pattern seen in nature. This pattern occurs when individuals in a population are grouped together in patches, often due to environmental factors, social behavior, or resource availability.

Question 5

Which set of values would result in a population with a growth rate of zero?
A) b = 1000, d = 500, i = 750, e = 1000
B) b = 1000, d = 500, i = 1000, e = 1000
C) b = 1000, d = 500, i = 1500, e = 1000
D) b = 1000, d = 500, i = 0, e = 1000
E) b = 1000, d = 500, i = 500, e = 1000

Accepted Answer

The answer of Which set of values would result in...

Question 6

Which of the following organisms would have the highest intrinsic rate of increase?
A) Bacteria
B) Blue whales
C) Red grouse
D) Elephants
E) Humans

Accepted Answer

Bacteria have the highest intrinsic rate of increase due to their rapid reproduction cycle, allowing populations to double in a very short period under optimal conditions.

Question 7

What would be the growth rate ( r ) of an island population of 1,000 that has 30 births per 100 population, 20 death per 100 population, 5 immigrants per 100 population, and 10 emigrants per 100 population?
A) +5
B) − 50
C) +50
D) − 150
E) +150

Accepted Answer

The growth rate (r) is calculated by subtracting the death rate and emigration rate from the birth rate and immigration rate. Here, (30 births + 5 immigrants) - (20 deaths + 10 emigrants) = 35 - 30 = +5 per 100 population. For a population of 1,000, this translates to a growth rate of +50.

Question 8

Which of the following series correctly represents the hierarchical organization within ecology?
A) Ecosystem → population → community → biosphere
B) Biosphere → community → population → ecosystem
C) Community → population → ecosystem → biosphere
D) Population → community → ecosystem → biosphere
E) Population → ecosystem → community → biosphere

Accepted Answer

The correct hierarchical organization within ecology, from smaller to larger units, is: Population (a group of individuals of the same species living in a particular area), Community (all the populations of different species that live and interact in an area), Ecosystem (a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system), and Biosphere (the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, hydrosphere, and atmosphere).

Question 9

At zero population growth:
A) b = d.
B) b > d.
C) b d.
D) r > 0.
E) r > K .

Accepted Answer

At zero population growth, the birth rate (b) equals the death rate (d), meaning no net increase or decrease in population size.

Question 10

The best definition of population density is the number of individuals:
A) of all species in a given area.
B) of one species in a given area.
C) in a given area at a given time.
D) of all species in a given area at a given time.
E) of one species in a given area at a given time.

Accepted Answer

Population density specifically refers to the number of individuals of one species in a given area at a given time, allowing for precise measurements and comparisons within ecological and biological studies.

Question 11

Which of the following is a correct statement regarding populations in biology?
A) A population is a group consisting of more than one species that all live together in a prescribed area at the same time
B) The boundaries of the area cannot be defined by an ecologist.
C) Populations exhibit characteristics distinctive from those of the individuals of which they are composed.
D) Populations have the same properties as communities.
E) Natural selection acts indirectly to produce adaptive changes in populations and directly affects the community level.

Accepted Answer

Populations exhibit unique characteristics such as population density, age structure, and distribution patterns that are not applicable to individual organisms. These characteristics emerge from interactions among individuals within the population and with their environment.

Question 12

What term refers to the average rate at which organisms produce offspring?
A) Doubling time
B) Natality
C) Emigration
D) Stasis
E) Survivorship

Accepted Answer

Natality refers to the birth rate or the average rate at which organisms produce offspring, indicating the number of births within a population over a specific period.

Question 13

When r = 0.00001, the population size:
A) will increase.
B) will decrease.
C) is stable.
D) may increase or decrease, depending on K .
E) may increase or decrease, depending on i .

Accepted Answer

When r (the intrinsic rate of natural increase) is greater than 0, it indicates that the population size will increase, regardless of other factors.

Question 14

Natural selection acts most directly on:
A) populations.
B) communities.
C) ecosystems.
D) the biosphere.
E) K- selected organisms.

Accepted Answer

Natural selection acts most directly on populations because it is the process by which individuals with certain heritable traits tend to survive and reproduce at higher rates than other individuals because of those traits, leading to changes in the traits of the population over time.

Question 15

Which of the following is NOT a condition that is likely to lead to clumped population dispersion?
A) Severe competition among individuals
B) Patchy distribution of resources in the environment
C) Presence of family groups and pairs
D) Limited seed dispersal or asexual reproduction
E) Pressure from predation

Accepted Answer

Severe competition among individuals typically leads to uniform dispersion, where individuals space themselves evenly to maximize access to resources, rather than clumped dispersion where individuals aggregate in patches due to factors like patchy resources, social groupings, limited dispersal mechanisms, or predation pressure.

Question 16

Figure 53-1 ​

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The graph in the accompanying figure would best be described as:
A) being characteristic of exponential growth.
B) being characteristic of arithmetic growth.
C) an S-shaped curve.
D) a J-shaped curve.
E) being a J-shaped curve characteristic of exponential growth.

Accepted Answer

The answer of Figure 53-1 ​

​
The graph in the accompanying...

Question 17

Figure 53-1 ​

​
The equation that would best describe the curve in the accompanying figure is:
A) dN / dt = r .
B) dN / dt = N .
C) dN / dt = rN .
D) dN / dt = rN + I − e .
E) dN / dt = rN ( K − N ).

Accepted Answer

The answer of Figure 53-1 ​

​
The equation that would best...

Question 18

The logistic equation:
A) models a J-shaped growth curve.
B) takes into account the carrying capacity of the environment.
C) predicts continued exponential growth.
D) characterizes the uncontrolled growth of a population.
E) models a K -shaped growth curve.

Accepted Answer

The logistic equation models population growth by taking into account the carrying capacity of the environment, which limits the size of the population that can be supported.

Question 19

Which of the following relationships is incorrectly paired?
A) Schooling fish-aggregated distribution
B) Nesting seabirds-random dispersion
C) Grove of aspen-clumped dispersion
D) Flour beetle larvae-random dispersion
E) Adult sand pine-uniform dispersion

Accepted Answer

Nesting seabirds typically exhibit a clumped dispersion pattern due to the need for specific nesting sites and social behaviors, not a random dispersion.

Question 20

Clumped dispersion is often influenced by:
A) the presence of strange groups.
B) sexual reproduction in plants or invertebrates.
C) unlimited seed dispersal in plants.
D) a patchy distribution of resources.
E) homogenous environments.

Accepted Answer

Clumped dispersion, where individuals are aggregated in patches, is often influenced by a patchy distribution of resources. This pattern occurs because individuals aggregate where resources such as food, shelter, or moisture are abundant.

Quiz 53: Introduction to Ecology: Population Ecology

Which of the following consists of organisms, all of which share a common gene pool?

Which of the following is NOT a condition that is likely to lead to uniform population dispersion?

When r = −0.00057, the population size:

What is perhaps the most common of the dispersal patterns seen in nature?

Which set of values would result in a population with a growth rate of zero?

Which of the following organisms would have the highest intrinsic rate of increase?

What would be the growth rate ( r ) of an island population of 1,000 that has 30 births per 100 population, 20 death per 100 population, 5 immigrants per 100 population, and 10 emigrants per 100 population?

Which of the following series correctly represents the hierarchical organization within ecology?

At zero population growth:

The best definition of population density is the number of individuals:

Which of the following is a correct statement regarding populations in biology?

What term refers to the average rate at which organisms produce offspring?

When r = 0.00001, the population size:

Natural selection acts most directly on:

Which of the following is NOT a condition that is likely to lead to clumped population dispersion?

Figure 53-1 The graph in the accompanying figure would best be described as:

Figure 53-1 The equation that would best describe the curve in the accompanying figure is:

The logistic equation:

Which of the following relationships is incorrectly paired?

Clumped dispersion is often influenced by: