Q: A population of deer in a forest is estimated using the mark-recapture method. In the first capture, 40 deer are marked and released. Later, 50 deer are captured, and 10 of them are marked. What is the estimated population size ($N$)? Use the formula $N = \frac{M \times n}{m}$, where $M$ is the number marked initially, $n$ is the total caught the second time, and $m$ is the number of marked recaptures.

$N = \frac{40 \times 50}{10} = 200$

Q: A population of rabbits grows according to the exponential growth model. If the intrinsic rate of increase ($r$) is $0.2$ per year and the current population size ($N$) is $100$, what will the population size be after one year? Use the formula $N_{t+1} = N_t e^{r}$.

$N_{t+1} = 100 \times e^{0.2} \approx 122$

Question 1

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

Accepted Answer

The maximum population size that an environment can sustain indefinitely, given the available resources.

Question 2

A population of deer in a forest is estimated using the mark-recapture method. In the first capture, 40 deer are marked and released. Later, 50 deer are captured, and 10 of them are marked. What is the estimated population size ($N$)? Use the formula $N = \frac{M 	imes n}{m}$, where $M$ is the number marked initially, $n$ is the total caught the second time, and $m$ is the number of marked recaptures.

Accepted Answer

$N = \frac{40 	imes 50}{10} = 200$

Question 3

Which of the following is an example of a density-dependent factor affecting population growth?

Accepted Answer

A disease that spreads more rapidly as population density increases.

Question 4

A population of rabbits grows according to the exponential growth model. If the intrinsic rate of increase ($r$) is $0.2$ per year and the current population size ($N$) is $100$, what will the population size be after one year? Use the formula $N_{t+1} = N_t e^{r}$.

Accepted Answer

$N_{t+1} = 100 	imes e^{0.2} \approx 122$

Question 5

Which scenario best illustrates the concept of habitat fragmentation?

Accepted Answer

A forest is divided into several smaller patches by roads and farmland, isolating animal populations.

Question 6

Which of the following best explains why ecologists study populations rather than individuals?

Accepted Answer

Population-level processes, such as birth and death rates, determine species survival and ecosystem dynamics.

Question 7

A population of fish in a lake is experiencing logistic growth. Which equation best describes the change in population size over time?

Accepted Answer

$\frac{dN}{dt} = rN \left(1 - \frac{N}{K}\right)$

Question 8

Which of the following is NOT a likely consequence of habitat fragmentation for a population?

Accepted Answer

Increased genetic diversity due to more migration between patches.

Question 9

A life table for a population shows high survivorship in early and middle life, followed by a rapid decline in survivorship in older age groups. Which type of survivorship curve does this represent?

Accepted Answer

Type I

Question 10

Which of the following variables is NOT directly used to calculate the per capita rate of increase ($r$) in a population?

Accepted Answer

Carrying capacity ($K$)

Question 11

If a population's net reproductive rate ($R_0$) is less than 1, what will happen to the population size over time?

Accepted Answer

It will decrease.

Question 12

Which of the following best describes a metapopulation?

Accepted Answer

A group of populations that are separated by space but interact through migration.

Question 13

A population of insects has a per capita birth rate of $0.4$ and a per capita death rate of $0.1$. What is the intrinsic rate of increase ($r$)?

Accepted Answer

$r = 0.4 - 0.1 = 0.3$

Question 14

Which of the following is a density-independent factor that can affect population size?

Accepted Answer

A severe drought

Question 15

Which of the following statements about exponential and logistic growth is correct?

Accepted Answer

Exponential growth occurs when resources are unlimited, while logistic growth includes the effect of carrying capacity.

Question 16

A country has an age pyramid with a broad base and a narrow top. What does this indicate about the country's population?

Accepted Answer

The population is growing rapidly due to a high proportion of young individuals.

Question 17

Which of the following best explains the trade-off between survivorship and fecundity in life history strategies?

Accepted Answer

Organisms that invest more energy in producing many offspring often have lower survivorship of each offspring.

Question 18

If a population is at zero population growth, which of the following must be true?

Accepted Answer

Birth rate equals death rate.

Question 19

Which of the following patterns of population distribution is most likely to result from strong competition for limited resources?

Accepted Answer

Uniform distribution

Question 20

A population of birds has a carrying capacity ($K$) of 500 and an intrinsic rate of increase ($r$) of 0.1. If the current population size ($N$) is 250, what is the expected population growth rate ($\frac{dN}{dt}$) according to the logistic growth equation $\frac{dN}{dt} = rN \left(1 - \frac{N}{K}\right)$?

Accepted Answer

$\frac{dN}{dt} = 0.1 	imes 250 	imes \left(1 - \frac{250}{500}ight) = 12.5$

Population Ecology: Concepts, Methods, and Applications

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