Question 1

Which of the following best describes the per-capita rate of increase ($$r) in a $$population?

Accepted Answer

The difference between the birthrate and death rate per individual.

Question 2

A population of bacteria is placed in a large flask with unlimited nutrients and no competition. Which type of growth will this population most likely exhibit?

Accepted Answer

Exponential growth, because $$r is $$constant and density independent.

Question 3

What is the equation for population growth rate when no immigration or emigration occurs?

Accepted Answer

$$\Delta N / \Delta t$$

Question 4

Which of the following scenarios is most likely to result in density-independent population growth?

Accepted Answer

A pair of birds that arrive on a previously uninhabited island.

Question 5

During which stage of logistic growth does the population growth rate ($$r) $$begin to decline?

Accepted Answer

When competition for density-dependent factors begins to occur.

Question 6

What happens to the population growth rate ($$r) as a $$population approaches its carrying capacity ($$K$$)?

Accepted Answer

$$r$$ decreases and eventually reaches zero.

Question 7

Which of the following best defines carrying capacity ($$K$$)?

Accepted Answer

The maximum number of individuals that can be supported in a particular habitat over a sustained period of time.

Question 8

A population of reindeer introduced to an island overshoots its carrying capacity and then crashes. What is the most likely explanation for this pattern?

Accepted Answer

The population used up nearly all available resources, causing a crash.

Question 9

Which of the following equations represents exponential population growth?

Accepted Answer

$$\frac{dN}{dt} = rN$$

Question 10

In the logistic growth model, what does the term $$\left(1 - \frac{N}{K}\right)$$ represent?

Accepted Answer

The reduction in growth rate as the population approaches carrying capacity.

Question 11

A population of Paramecium caudatum in a laboratory shows a sigmoidal (S-shaped) growth curve. What does this indicate about the population's growth dynamics?

Accepted Answer

The population is experiencing logistic growth with density-dependent regulation.

Question 12

If a population's birth rate equals its death rate, what is the value of $$r$$ and what happens to the population size?

Accepted Answer

$$r = 0$$; the population size remains stable.

Question 13

Which of the following is a real-world example of a population experiencing a genetic bottleneck?

Accepted Answer

A population that has been devastated by a catastrophe and begins to recover with a few surviving individuals.

Question 14

Which of the following factors can cause the carrying capacity ($$K) of a $$habitat to change over time?

Accepted Answer

Destruction of resources, such as overgrazing by a population.

Question 15

A small group of birds colonizes a new island. Which stage of population growth will they most likely experience first?

Accepted Answer

Exponential growth, as resources are abundant and competition is minimal.

Question 16

Which of the following best explains why exponential growth is rarely sustained in natural populations?

Accepted Answer

Resources become limited and density-dependent factors slow growth.

Question 17

If a population is growing at its intrinsic rate of increase ($$r_{max}$$), which of the following must be true?

Accepted Answer

Environmental conditions are ideal and resources are unlimited.

Question 18

Which of the following is an example of a density-dependent factor that can regulate population growth?

Accepted Answer

Competition for food resources.

Question 19

A population of lichen (Cladonia rangiferina) is the primary winter food source for reindeer. If the reindeer population overshoots the carrying capacity, what is a likely consequence for the lichen population?

Accepted Answer

The lichen population will decrease due to overgrazing.

Question 20

Which of the following best describes the shape of a logistic growth curve?

Accepted Answer

S-shaped, with rapid initial growth that slows as the population approaches carrying capacity.

Population Growth Dynamics: Exponential and Logistic Models

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