ENV 101 Exam 3 V1 | ENV 101
Environmental Science | StraighterLine |
Q&A with Rationale (StraighterLine
ENV101 Exam 3)
1. What term describes the maximum population size of a species that a specific environment
can sustain over the long term?
A. Carrying capacity
B. Environmental resistance
C. Biotic potential
D. Exponential growth
Answer: A
Rationale: The carrying capacity refers to the limit of a population size that an ecosystem’s
resources can support. It is determined by factors such as food availability, water supply,
and habitat space. When a population exceeds this level, it typically experiences a dieback
or crash due to resource depletion.
2. In the context of population growth, what does a ‘J-shaped’ curve represent?
A. Logistic growth
B. Linear progression
C. Stable equilibrium
,D. Exponential growth
Answer: D
Rationale: Exponential growth occurs when a population increases at a constant rate per
unit of time, resulting in a J-shaped curve. This type of growth is common in species that
have abundant resources and little competition. However, this growth cannot be sustained
indefinitely in a finite environment.
3. Which of the following is considered a density-independent factor that regulates
population size?
A. Disease
B. A catastrophic forest fire
C. Competition for food
D. Predation
Answer: B
Rationale: Density-independent factors affect populations regardless of their size or
density within an area. Natural disasters like fires, floods, and volcanic eruptions are
primary examples of such factors. In contrast, factors like disease and competition vary in
intensity based on how crowded the population is.
4. During which stage of the Demographic Transition Model do birth rates remain high while
death rates drop sharply?
A. Stage 1 (Pre-industrial)
, B. Stage 3 (Industrial)
C. Stage 2 (Transitional)
D. Stage 4 (Post-industrial)
Answer: C
Rationale: The transitional stage is characterized by improved hygiene, medical care, and
food production which lower the death rate. Because birth rates remain high due to
cultural momentum, the population undergoes rapid expansion. This stage is typical of
many developing nations today.
5. What is the primary definition of ‘Total Fertility Rate’ (TFR)?
A. The number of births per 1,000 people in a year
B. The average number of children born to a woman during her lifetime
C. The percentage of a population that is of reproductive age
D. The rate at which a population replaces itself
Answer: B
Rationale: Total Fertility Rate is a key demographic indicator that estimates the average
number of children a woman will have in her childbearing years. A TFR of 2.1 is generally
considered the replacement level in developed countries. It is influenced by factors such as
education, economic status, and access to family planning.
Environmental Science | StraighterLine |
Q&A with Rationale (StraighterLine
ENV101 Exam 3)
1. What term describes the maximum population size of a species that a specific environment
can sustain over the long term?
A. Carrying capacity
B. Environmental resistance
C. Biotic potential
D. Exponential growth
Answer: A
Rationale: The carrying capacity refers to the limit of a population size that an ecosystem’s
resources can support. It is determined by factors such as food availability, water supply,
and habitat space. When a population exceeds this level, it typically experiences a dieback
or crash due to resource depletion.
2. In the context of population growth, what does a ‘J-shaped’ curve represent?
A. Logistic growth
B. Linear progression
C. Stable equilibrium
,D. Exponential growth
Answer: D
Rationale: Exponential growth occurs when a population increases at a constant rate per
unit of time, resulting in a J-shaped curve. This type of growth is common in species that
have abundant resources and little competition. However, this growth cannot be sustained
indefinitely in a finite environment.
3. Which of the following is considered a density-independent factor that regulates
population size?
A. Disease
B. A catastrophic forest fire
C. Competition for food
D. Predation
Answer: B
Rationale: Density-independent factors affect populations regardless of their size or
density within an area. Natural disasters like fires, floods, and volcanic eruptions are
primary examples of such factors. In contrast, factors like disease and competition vary in
intensity based on how crowded the population is.
4. During which stage of the Demographic Transition Model do birth rates remain high while
death rates drop sharply?
A. Stage 1 (Pre-industrial)
, B. Stage 3 (Industrial)
C. Stage 2 (Transitional)
D. Stage 4 (Post-industrial)
Answer: C
Rationale: The transitional stage is characterized by improved hygiene, medical care, and
food production which lower the death rate. Because birth rates remain high due to
cultural momentum, the population undergoes rapid expansion. This stage is typical of
many developing nations today.
5. What is the primary definition of ‘Total Fertility Rate’ (TFR)?
A. The number of births per 1,000 people in a year
B. The average number of children born to a woman during her lifetime
C. The percentage of a population that is of reproductive age
D. The rate at which a population replaces itself
Answer: B
Rationale: Total Fertility Rate is a key demographic indicator that estimates the average
number of children a woman will have in her childbearing years. A TFR of 2.1 is generally
considered the replacement level in developed countries. It is influenced by factors such as
education, economic status, and access to family planning.
