Ch 30

Their availability influences the ______________ of individuals within a population.

spatial distribution

This study is important because it offers information key to the survival of all ___________, including humans through microbes.

species

Finally, the carrying capacity is reached during the _____________________ phase where birth and death rates are equal.

stable equilibrium

Life tables can be used to construct _________________ by plotting the number of survivors per 1,000 ___________ against ____.

survivorship curves, births, age

what are the factors that lead to extinction of species?

1. tend to exhibit equilibrium life history patterns 2. increased resource use by humans 3. narrow habitat tolerance 4. small local populations 5. restricted geographic range 6. increased human activity in previously unsettled areas

define density-independent factors

1. abiotic factors such as weather or natural disasters 2. a tornado destroys half of the trees in a forest

define density-dependent factors

1. competition drives part of a deer population to starvation 2. as lynx populations increase, hare populations decrease. As hare population decrease, lynx populations decrease, causing a shifting rise in hare populations again 3. there are fewer nesting sites than pairs of woodpeckers that need nests. As a result, some woodpeckers do not have successful clutches. 4. biotic factors such as competition, predation, and parasitism 5. an insect population is too large for all to find sufficient camouflage within a flower patch, so many become subject to predation

what are the factors most likely to influence biotic potential?

1. how often each individual reproduces 2. abundance of resources 3. usual number of offspring per reproduction 4. age at which reproduction 5. chances of survival until age of reproduction

what are the characteristics of equilibrium pattern

1. large individuals 2. slow to mature 3. much care of offspring 4. long life span 5. few offspring

describe less-developed countries (LDCs)

1. overpopulation is obvious in these countries 2. pyramid graph 3. growth rate upwards of 1.5%

describe more-developed countries (MDCs)

1. overuse of resources is obvious in these countries 2. skinny graph 3. growth rate around 0.2%

what are the characteristics of opportunistic pattern

1. small individuals 2. fast to mature 3. little or no care of offspring 4. short life span 5. many offspring

Such exponential growth results in a(n) ____-shaped growth curve when graphed because the growth rate is positive.

J

Logistic growth results in a(n) __-shaped growth curve when graphed.

S

What is the correct ratio of fossil fuel consumption between the MDCs and LDCs? a. MDCs 60% vs. LDCs 40% b. MDCs 40% vs. LDCs 60% c. MDCs 22% vs. LDCs 78% d. MDCs 50% vs. LDCs 50% e. MDCs 80% vs. LDCs 20%

a. MDCs 60% vs. LDCs 40% Explanation MDCs consume approximately 60% of the world's fossil fuels, while the LDCs consume approximately 40%.

Which of the following statements is correct about the comparison between MDCs and LDCs? a. MDCs consume 4 times as many metals and 3 times as much paper as LDCs. b. MDCs consume twice as much paper and 4 times as many metals as LDCs. c. The population of MDCs is growing twice as fast as the population of LDCs. d. MDCs produce 10 times as much hazardous waste and consume 3 times as much paper as LDCs. e. MDCs consume 3 times as many metals and 4 times as much paper as LDCs.

a. MDCs consume 4 times as many metals and 3 times as much paper as LDCs. Explanation MDCs make up 22% of the population and LDCs make up 78%.MDCs produce 90% of the hazardous wastes and LDCs produce 10%.MDCs consume 60% of the fossil fuels and LDCs consume 40%.MDCs consume 80% of the metals and LDCs consume 20%.MDCs consume 75% of the paper and LDCs consume 25%.

Based upon the features listed, which of the following species is the most likely to go extinct? a. Species A has a small population, has a narrow habitat tolerance, and lives on an island. b. Species B has a large population, can withstand a large spectrum of environmental conditions, and lives all over the United States. c. Species C has a small population, can withstand a large spectrum of environmental conditions, and lives within a small section of the forest. d. Species D has a moderate population, can withstand a moderate spectrum of environmental conditions, and lives on an island. e. Species E has a large local population, broad tolerance to environmental change, and a large geographic range.

a. Species A has a small population, has a narrow habitat tolerance, and lives on an island. Explanation Three factors help determine if a species is likely to go extinct or not: the size of the geographic range, degree of habitat tolerance, and size of local populations. If the geographic range is small, the population is small, and the species cannot tolerate environmental change, it has the highest risk of going extinct.

What is the greatest problem that the human population will face if we fail to have a greater understanding of ecology and environmental science? a. We will have a lack of understanding about the problems that the human population poses to the health of the biosphere. b. We will have a lack of understanding about the ability of the human population to obtain additional resources from the environment. c. We will not understand how to expand human society into currently uninhabited areas on the planet. d. The human population will start to decline in size. e. The human population will go extinct in the near future.

a. We will have a lack of understanding about the problems that the human population poses to the health of the biosphere. Explanation Comprehension of ecological principles helps us understand why a functioning biosphere is critical to our survival and why our population of over 7 billion people and our overconsumption of resources pose threats to the biosphere. Without a healthy biosphere, the human population will not be able to sustain itself and will eventually see a significant decrease in size.

Jacob is studying a population of wrens in Michigan. During one severe winter, 5% of the birds died due to starvation and cold temperatures. Severe weather is an example of a. a density-independent factor. b. a negative growth rate. c. a density-dependent factor. d. an opportunistic population. e. logistic growth.

a. a density-independent factor. Explanation Abiotic factors such as weather are examples of density-independent factors.

Which field of biology studies all aspects of biodiversity? a. conservation biology b. histology c. geology d. entomology e. environmental science

a. conservation biology Explanation Conservation biology is a discipline of ecology that studies all aspects of biodiversity, with the goal of conserving natural resources, including wildlife, for the benefit of this generation and future generations.

Which of the following is an example of a density-dependent factor? a. parasite infection b. a wildfire c. a tornado d. flooding e. freezing temperatures

a. parasite infection Explanation The percentage of animals that are parasitized will increase as the density of the population increases.

Organisms are more likely to face extinction if they have which of the following characteristics? a. restricted geographic ranges b. broad habitat tolerance c. large local populations d. extensive geographic ranges e. high biotic potential

a. restricted geographic ranges Explanation If animals have restricted geographic ranges, they may not be able to avoid factors leading to decreases in the population e.g., habitat destruction, poaching, disease, etc.

However, as the population size grows, the growth rate will _____________ during what is called the exponential growth phase.

accelerate

The _______________ is a demographic characteristic of populations that can be used to predict future population outcomes by looking at the distribution of ________ within a population.

age structure, ages

Which of the following is true about the majority of less-developed countries (LDCs)? a. They consume the most fossil fuels. b. They support the highest populations. c. They produce the most hazardous wastes. d. They have the largest environmental impact. e. They exhibit the highest per capita resource consumption.

b. They support the highest populations. b. They support the highest populations.

The current global ___________ is estimated to be 19.14 per 1,000 per year, while the global _____________ is estimated to be 7.99 per 1,000 per year.

birthrate, death rate

The rate of population growth depends on the ____________, or the number of people born each year, and the ___________, or the number of people who die each year.

birthrate, death rate

If the ___________ exceeds the ______________, then population growth will increase; however, if the _______________ exceeds the ______________, then the population will decrease.

birthrate, death rate, death rate, birthrate

Which of the following is an example of exponential growth? a. 2,000→2,000→2,000 b. 1,500→1,600→1,700 c. 1,500→1,550→2,010 d. 1,000→1,500→2,000 e. 2,000→1,500→1,000

c. 1,500→1,550→2,010 Explanation The population must show accelerating growth. The growth lags at first and then accelerates.

Which of the following is true about the current state of human population growth? a. The 21st century has seen the highest global human population growth. b. Human populations tend to be evenly distributed. c. After the Industrial Revolution, population growth increased. d. The current global death rate exceeds the current global birthrate. e. The doubling time for the human population is increasing.

c. After the Industrial Revolution, population growth increased. Explanation After the Industrial Revolution, there was an increase in jobs and increased productivity associated with food. As a result, the growth curve began to increase rapidly.

A butterfly species has very wide distribution across southern Florida. In addition, the adults and caterpillars can use a wide array of plant species as a food source and also tolerate a broad range of temperatures. Based on these criteria, this species is unlikely to face extinction in the immediate future. a. True, because they have a restricted geographic range. b. False, because they have an extensive geographic range. c. True, because they have broad habitat tolerances. d. False, because all the local populations on the mainland and island are small. e. True, because they have narrow habitat tolerances.

c. True, because they have broad habitat tolerances. Explanation The statement is true. In addition, organisms are less likely to face extinction if they have broad habitat tolerances and an extensive geographic range.

Which of the following statements regarding biotic potential is true? a. Most populations do not reach their biotic potential because of competition and limitations in the environment, but instead reach their carrying capacity, which is the maximum population that can be sustained by an ecosystem. b. All populations reach their biotic potential because that is the maximum population that can be sustained by an ecosystem. c. Two of these choices are correct. Most populations do not reach their biotic potential because of competition and limitations in the environment, but instead reach their carrying capacity, which is the maximum population that can be sustained by an ecosystem AND only organisms that exhibit exponential growth are capable of reaching their biotic potential. d. Only populations that exhibit exponential growth are capable of reaching their biotic potential because they generally contribute their biotic potential to the next generation. e. Only populations that exhibit logistic growth reach their biotic potential because only here do populations grow steadily enough to reach their biotic potential.

c. Two of these choices are correct. Most populations do not reach their biotic potential because of competition and limitations in the environment, but instead reach their carrying capacity, which is the maximum population that can be sustained by an ecosystem AND only organisms that exhibit exponential growth are capable of reaching their biotic potential. Explanation This is correct. Most populations do not reach their biotic potential because of competition and limitations in the environment, but instead reach their carrying capacity which is the maximum population that can be sustained by an ecosystem. Only organisms that exhibit exponential growth are capable of reaching their biotic potential.

Which of the following best describes a population? a. all the members of a given species over a broad range of areas b. all the living members of an ecosystem that interact with each other c. a group of individuals of the same species in a given area that reproduce d. a group of individuals within their environment, including both biotic and abiotic components

c. a group of individuals of the same species in a given area that reproduce

Different populations living in the same geographical region is a(n) a. organism. b. population. c. community. d. ecosystem. e. biosphere.

c. community. Explanation An organism is an individual living thing; a population is organisms of the same species living in an area; a community is different populations living in the same geographical region; an ecosystem is all abiotic and biotic factors in a particular geographical region; and the biosphere is the portion of the Earth where living organisms are found.

The growth rate continues to rise in some Asian countries. This is because a. there is a higher number of reproductive individuals compared to postreproductive individuals. b. there is a higher number of postreproductive and reproductive individuals compared to prereproductive individuals. c. there is a higher number of prereproductive and reproductive individuals compared to postreproductive individuals. d. there is an equal number of prereproductive and reproductive individuals. e. there are more postreproductive individuals compared to prereproductive individuals.

c. there is a higher number of prereproductive and reproductive individuals compared to postreproductive individuals. Explanation A population that is growing has more individuals in the pre- and reproductive age groups and thus the age structure diagram resembles a pyramid.

All of the following are true of BOTH logistic growth and exponential growth except a. they both have a lag phase. b. they both have an exponential growth phase. c. they both have a stable equilibrium phase. d. they are both a type of population growth. e. they are influenced by resource availability.

c. they both have a stable equilibrium phase. Explanation Logistic growth reaches a carrying capacity due to the limited number of resources.

The pattern of distribution exhibited by the young, small desert shrubs is an example of ___________ distribution.

clumped

On every continent, human population densities are highest along the __________.

coasts

At the _____________ level, ecologists study the interactions between various populations at the same locale.

community

Exponential growth slows as _____________ for resources increases during the deceleration phase.

competition

A discipline of ecology that studies all aspects of biodiversity is ____________________, which has the goal of conserving natural resources.

conservation biology

Which of the following statements regarding carrying capacity is not true? a. Organisms that exhibit logistic growth reach their carrying capacity, while organisms that exhibit exponential growth do not. b. Organisms reach carrying capacity because of environmental resistance including competition over resources and other environmental limitations. c. The presence of carrying capacity is what distinguishes exponential growth from logistic growth. d. All of the answer choices are correct.

d. All of the answer choices are correct.

In which of the following areas is human population growth the lowest? a. Africa b. North America c. Australia d. Europe e. South America

d. Europe Explanation See Figure 30.4. Many countries in Europe have negative growth because of very low birthrates.

Insects and bacteria typically exhibit a. exponential growth. b. logistic growth. c. growth that results in a J-shaped curve. d. Two choices are correct: These organisms exhibit exponential growth that results in a J-shaped curve. e. Two answers are correct: These organisms exhibit logistic growth that results in a J-shaped curve.

d. Two choices are correct: These organisms exhibit exponential growth that results in a J-shaped curve.

During a recent hurricane, 25 individuals of the same butterfly species were blown onto a barrier island in southern Florida. The hurricane which lead to the arrival of the butterflies on the island is an example of a _____ factor. a. clumped b. random c. density-dependent d. density-independent e. dispersed

d. density-independent Explanation Density-independent factors include abiotic factors such as weather, for example hurricanes.

Jacob is studying a population of wrens in Michigan. Over several years, he notices that the population always stabilizes at around 45 individuals. What is the reason for this? a. population is at maximum density b. death rate is higher than birthrate c. exponential growth d. limited resources to support additional birds e. slow lag phase

d. limited resources to support additional birds Explanation The carrying capacity is the maximum number of individuals that the environment can sustain.

The exponential growth phase can only continue as long as _____________ in the environment are sufficient.

resources

All of the following are true about human population growth except a. the majority of the world's human population live in Asia. b. the Black Plague resulted in a decreased growth rate in the 1300s. c. changes during the Industrial Revolution led to a steep rise in the human population. d. we will reach the Earth's carrying capacity within the next 20 years. e. human population densities tend to be highest along the coasts.

d. we will reach the Earth's carrying capacity within the next 20 years. Explanation Although human population growth is a major concern, we still do not know the actual carrying capacity of the Earth.

During a recent hurricane, 25 individuals of the same butterfly species were blown onto a barrier island in southern Florida. Prior to this event, this species did not inhabit the island, but with the ample vegetation on the island and a lack of predators, the displaced individuals were able to survive and reproduce. After several years, the population stabilized with approximately 150 individuals. The 150 individuals on the island is an example of the a. density-dependent factors. b. biotic potential. c. exponential growth. d. logistic growth. e. carrying capacity.

e. carrying capacity. Explanation The maximum number of individuals that an environment can sustain is the carrying capacity. This is where the population growth rate stabilizes.

The study of organisms interacting with each other and their physical environment is known as _____________.

ecology

It is also important for ecologists to study how various communities are affected by the physical environment within a(n) _____________ over time.

ecosystem

The field of ___________________ applies ecology principles to practical human concerns.

environmental science

As the population size grows, the growth rate will accelerate due to biotic potential during what is called the ___________ growth phase.

exponential

Growth of a population in which the increase occurs in the same manner as compound interest in banking is termed _______________.

exponential

This growth curve exhibits ________ distinct phases over time.

four

Therefore, the world population is ______________ at a rate of 1.11% per year.

increasing

The _____ phase exhibits a slow growth rate due to the small number of individuals within the population early on.

lag

The____ phase exhibits a slow growth rate due to the small number of individuals within the population early on.

lag

The components of an environment that support its organisms are called its ______________, and include light, water, food, mates, and __________.

resources, space

Some ecologists study an individual ____________, focusing on its adaptations to a particular environment.

organism

Organisms are usually part of a(n) _____________, which is a group of individuals of the same species in a given location at the same time.

population

The pattern of distribution exhibited by the medium shrubs is an example of ___________ distribution.

random

This growth curve exhibits ______ distinct phases over time.

two

The pattern of distribution exhibited by the large shrubs is an example of __________ distribution.

uniform