Q: Given a population of 1,000 bacteria with a per capita birth rate ($$b) of 0.8 $$and a per capita death rate ($$d) of 0.1$$, what is the population growth ($$G) $$after one time unit? Use the formulas $$r = b - d$$ and $$G = rN.$$

$$G = (0.8 - 0.1) \times 1,000 = 700$$

Q: A population of deer in a forest has a birth rate ($$b) of 0.2 $$and a death rate ($$d) of 0.4. If $$the initial population ($$N) is 500$$, what is the growth rate ($$r) $$and total growth ($$G$$)?

$$r = 0.2 - 0.4 = -0.2;\ G = -0.2 \times 500 = -100$$

Question 1

Which of the following best defines a population in ecological terms?

Accepted Answer

A group of individuals of the same species living in the same area at the same time.

Question 2

Given a population of 1,000 bacteria with a per capita birth rate ($$b) of 0.8 $$and a per capita death rate ($$d) of 0.1$$, what is the population growth ($$G) $$after one time unit? Use the formulas $$r = b - d$$ and $$G = rN.$$

Accepted Answer

$$G = (0.8 - 0.1) 	imes 1,000 = 700$$

Question 3

Which of the following scenarios best illustrates density-independent regulation of a population?

Accepted Answer

A drought that causes massive die-off regardless of population size.

Question 4

A population of deer in a forest has a birth rate ($$b) of 0.2 $$and a death rate ($$d) of 0.4. If $$the initial population ($$N) is 500$$, what is the growth rate ($$r) $$and total growth ($$G$$)?

Accepted Answer

$$r = 0.2 - 0.4 = -0.2;\ G = -0.2 	imes 500 = -100$$

Question 5

Which of the following best describes the carrying capacity ($$K) of an $$ecosystem?

Accepted Answer

The maximum population size that an ecosystem can support sustainably.

Question 6

Which growth model is characterized by a J-shaped curve and what does this imply about the population's environment?

Accepted Answer

Exponential growth; the population is experiencing little environmental resistance.

Question 7

Which of the following is NOT a factor contributing to a species' biotic potential?

Accepted Answer

Carrying capacity of the environment

Question 8

In a forest, two bird species compete for the same beetle prey. What type of competition is this, and what is a likely ecological outcome?

Accepted Answer

Interspecific competition; one species may outcompete the other, leading to resource partitioning or exclusion.

Question 9

Which survivorship curve is most typical of humans in developed countries?

Accepted Answer

Type I (late loss)

Question 10

Which of the following best describes an r-selected species?

Accepted Answer

Short lifespan, many offspring, little parental care

Question 11

A country with a broad-based age structure diagram is most likely to experience which of the following?

Accepted Answer

Rapid population growth typical of less developed countries

Question 12

If a population's replacement-level fertility (RLF) is 2.1 but the actual fertility rate is 1.9, which factor could still cause the population to grow?

Accepted Answer

High immigration rates

Question 13

Which of the following is a density-dependent factor that regulates population size?

Accepted Answer

Predation

Question 14

A population of elephant seals is recovering with an initial population ($$N) of 100$$, a birth rate ($$b) of 0.5$$, and a death rate ($$d) of 0.2. $$What is the growth rate ($$r) $$and total growth ($$G$$)?

Accepted Answer

$$r = 0.5 - 0.2 = 0.3;\ G = 0.3 	imes 100 = 30$$

Question 15

Which of the following best explains why logistic growth curves (S-shaped) eventually level off?

Accepted Answer

Environmental resistance increases as the population approaches carrying capacity.

Question 16

Which survivorship curve is most typical of a giant sequoia tree, which produces many seeds but few survive to maturity?

Accepted Answer

Type III (early loss)

Question 17

Which of the following is a likely social or economic implication of a country with a fertility rate below replacement level but high immigration?

Accepted Answer

Population will continue to grow, potentially increasing demand for resources and services.

Question 18

Which of the following is an example of a density-independent factor affecting population regulation?

Accepted Answer

A severe hurricane

Question 19

Which of the following best describes the biosphere?

Accepted Answer

The entire portion of Earth inhabited by life.

Question 20

Which of the following is a characteristic of K-selected species?

Accepted Answer

Long lifespan, few offspring, substantial parental care

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