Q: A population of deer in a forest is estimated using the mark-recapture method. If 40 deer are marked and released, and later 100 deer are captured with 10 marked individuals among them, what is the estimated population size ($$N$$)? Use the formula $$N = \frac{sn}{x}$$, where $$s is $$the number marked, $$n is $$the number captured, and $$x is $$the number of marked recaptures.

$$N = \frac{40 \times 100}{10} = 400$$

Q: A population of mice in a field has a birth rate of 0.10 per year and a death rate of 0.08 per year. If the population size is 500, what is the expected change in population size ($$\Delta N) $$over one year?

$$\Delta N = rN = (0.10 - 0.08) \times 500 = 0.02 \times 500 = 10$$

Question 1

Which of the following best describes the concept of carrying capacity ($$K) in $$population ecology?

Accepted Answer

The maximum number of individuals that can be supported indefinitely by the resources available in a habitat.

Question 2

A population of deer in a forest is estimated using the mark-recapture method. If 40 deer are marked and released, and later 100 deer are captured with 10 marked individuals among them, what is the estimated population size ($$N$$)? Use the formula $$N = \frac{sn}{x}$$, where $$s is $$the number marked, $$n is $$the number captured, and $$x is $$the number of marked recaptures.

Accepted Answer

$$N = \frac{40 	imes 100}{10} = 400$$

Question 3

Which survivorship curve type (I, II, or III) is most likely to be observed in a population of elephants, and why?

Accepted Answer

Type I, because most individuals survive to old age and mortality increases late in life.

Question 4

Which equation best represents the exponential growth of a population?

Accepted Answer

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

Question 5

A population of rabbits has a per capita birth rate ($$b) of 0.06 $$and a per capita death rate ($$d) of 0.02. $$What is the per capita rate of increase ($$r$$)?

Accepted Answer

$$r = b - d = 0.06 - 0.02 = 0.04$$

Question 6

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

Accepted Answer

Competition for resources

Question 7

In the logistic growth model, what happens to the population growth rate as the population size ($$N) $$approaches the carrying capacity ($$K$$)?

Accepted Answer

The growth rate decreases and approaches zero.

Question 8

Which formula describes the logistic growth of a population?

Accepted Answer

$$\frac{dN}{dt} = rN \left( \frac{K-N}{K} \right)$$

Question 9

Which pattern of dispersion is most likely to result from territorial behavior in animals?

Accepted Answer

Uniform dispersion

Question 10

A population of mice in a field has a birth rate of 0.10 per year and a death rate of 0.08 per year. If the population size is 500, what is the expected change in population size ($$\Delta N) $$over one year?

Accepted Answer

$$\Delta N = rN = (0.10 - 0.08) 	imes 500 = 0.02 	imes 500 = 10$$

Question 11

Which of the following best explains why populations rarely exhibit perfect logistic growth in nature?

Accepted Answer

Environmental conditions fluctuate and carrying capacity ($$K) $$can change over time.

Question 12

Which life history trait is most likely to be favored in an unstable environment with frequent disturbances?

Accepted Answer

High reproductive rates and early maturity (r-selection)

Question 13

Which of the following mechanisms is NOT a density-dependent factor regulating population growth?

Accepted Answer

Seasonal drought

Question 14

A population of insects shows a Type III survivorship curve. Which of the following characteristics is most likely true for this population?

Accepted Answer

Most individuals die young, but a few survive to reproduce.

Question 15

Which of the following is an example of a biotic factor that can influence population growth?

Accepted Answer

Predation

Question 16

If a population is experiencing negative growth, which of the following is most likely true?

Accepted Answer

The death rate exceeds the birth rate.

Question 17

Which of the following best describes a population cycle, such as the snowshoe hare and lynx cycle?

Accepted Answer

Regular fluctuations in population size due to interactions between species and environmental factors.

Question 18

Which of the following is a direct consequence of increased population density on disease transmission?

Accepted Answer

Disease spreads more rapidly due to closer contact among individuals.

Question 19

Which of the following statements about human population growth is supported by current data?

Accepted Answer

The human population is no longer growing exponentially but is still increasing rapidly.

Chapter 53: Population Ecology – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards