Q: A population of deer in a forest is estimated using the mark-recapture method. If 50 deer are marked and released, and later 200 deer are captured with 10 marked individuals among them, what is the estimated population size ($$N$$)? Use the formula $$N = \frac{M \times C}{R}$$, where $$M is $$the number marked, $$C is $$the total captured, and $$R is $$the number recaptured.

$$N = \frac{50 \times 200}{10} = 1000$$

Q: Given the exponential growth equation $$N_t = N_0$ e$$^{rt}$$, what will be the population size after 5 years if the initial population (N_0$) is 100, and the intrinsic rate of increase (r$) is 0.2?

$$N_t = 100 \times e$$^{0.2 \times 5}$$ \approx 271.8$$

Q: A population of rabbits has a per-capita rate of increase ($$r) of 0.1 $$per month and a carrying capacity ($$K) of 500. If $$the current population size ($$N) is 100$$, what is the expected change in population size ($$\Delta N) in $$one month using the logistic growth equation $$\Delta N = rN \left(1 - \frac{N}{K}\right)$$?

$$\Delta N = 0.1 \times 100 \times \left(1 - \frac{100}{500}\right) = 0.1 \times 100 \times 0.8 = 8$$

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 50 deer are marked and released, and later 200 deer are captured with 10 marked individuals among them, what is the estimated population size ($$N$$)? Use the formula $$N = \frac{M 	imes C}{R}$$, where $$M is $$the number marked, $$C is $$the total captured, and $$R is $$the number recaptured.

Accepted Answer

$$N = \frac{50 	imes 200}{10} = 1000$$

Question 3

Which of the following factors is considered density-dependent in regulating population growth?

Accepted Answer

Competition for food resources

Question 4

Which survivorship curve type (I, II, or III) is most characteristic of humans in developed countries, and what does it indicate?

Accepted Answer

Type I; most individuals survive to old age, with high mortality late in life.

Question 5

Given the exponential growth equation $$N_t = N_0$ e$$^{rt}$$, what will be the population size after 5 years if the initial population (N_0$) is 100, and the intrinsic rate of increase (r$) is 0.2?

Accepted Answer

$$N_t = 100 	imes e$$^{0.2 	imes 5}$$ \approx 271.8$$

Question 6

Which statement best explains the difference between exponential and logistic population growth?

Accepted Answer

Exponential growth occurs when resources are unlimited, while logistic growth incorporates resource limitations and carrying capacity.

Question 7

A population of rabbits has a per-capita rate of increase ($$r) of 0.1 $$per month and a carrying capacity ($$K) of 500. If $$the current population size ($$N) is 100$$, what is the expected change in population size ($$\Delta N) in $$one month using the logistic growth equation $$\Delta N = rN \left(1 - \frac{N}{K}\right)$$?

Accepted Answer

$$\Delta N = 0.1 	imes 100 	imes \left(1 - \frac{100}{500}ight) = 0.1 	imes 100 	imes 0.8 = 8$$

Question 8

Which of the following is a consequence of habitat fragmentation on populations?

Accepted Answer

Reduced gene flow and increased risk of local extinction

Question 9

Which method would a biologist use to estimate the population size of a mobile animal species, such as fish in a lake?

Accepted Answer

Mark-recapture study

Question 10

If a population pyramid for a country shows a broad base and a narrow top, what does this indicate about the population?

Accepted Answer

The population has a high birth rate and is likely to grow rapidly.

Question 11

Which of the following best describes a metapopulation?

Accepted Answer

A group of spatially separated populations of the same species that interact through migration.

Question 12

Which variable is most likely to increase as a population approaches its carrying capacity ($$K$$)?

Accepted Answer

Competition for resources

Question 13

A population of insects has a net reproductive rate ($$R_0) of 1.5. $$What does this indicate about the population?

Accepted Answer

The population is increasing because each generation is producing more offspring than itself.

Question 14

Which of the following is NOT a density-independent factor affecting population size?

Accepted Answer

Floods

Question 15

Why do life tables provide important information for ecologists studying populations?

Accepted Answer

They allow ecologists to estimate survival and reproductive rates at different ages.

Question 16

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

Accepted Answer

Species with high fecundity often have low survivorship of offspring.

Question 17

Which population growth model is most appropriate for a population that initially grows rapidly but then levels off as resources become limited?

Accepted Answer

Logistic growth model

Question 18

If the per-capita rate of increase ($$r) is $$negative, what will happen to the population size over time?

Accepted Answer

The population will decrease.

Question 19

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

Accepted Answer

An outbreak of disease spreading more rapidly in crowded conditions.

Question 20

Which equation would you use to calculate the per-capita rate of increase ($$r) in a $$population?

Accepted Answer

$$r = b - d$$

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