chapter 12 biology
Stage 4: The birth rate reaches the same low level as the death rate, so population growth slows to ____________.
0
Stage ____________: High birth and death rates lead to slow population growth.
1
Today, no country remains in Stage ____________ of the demographic transition.
1
Scientists have identified about ____________ million species alive today.
1.9
identified species alive today
1.9 million
Homo sapiens arose only about ____________ years ago in Africa.
200,000
The human population is now growing by more than ____________ people a day.
200,000
. A stage 5 population can be dangerous, as (a) a younger population must support an older population. (b) there is a high death rate. (c) the birth rate is too large for the population to support. (d) none of the above
A
. K-selected species (a) live in stable environments. (b) population growth is controlled by density-independent factors. (c) have the potential for rapid population growth. (d) usually have a population size well below the carrying capacity.
A
. Problems associated with the ozone hole include (a) more skin cancer in people. (b) disruption of the water cycle. (c) disruption of terrestrial food webs. (d) all of the above.
A
. Renewable resources include (a) wind and sunlight. (b) fossil fuels. (c) nuclear power. (d) all of the above.
A
. The relationship between the greenhouse effect and global warming is best described by which statement? (a) The increase in the greenhouse effect has led to global warming. (b) The increase in global warming has led to the greenhouse effect. (c) The decrease in global warming has led to the greenhouse effect. (d) The decrease in the greenhouse effect has led to global warming.
A
. Why is it thought that there are very few climax communities today? (a) Because it is believed that continual change is normal in most ecosystems. (b) Because a community must be undisturbed for 10,000 years to be considered a climax community. (c) Because a climax community can only be a completely developed forest ecosystem. (d) all of the above
A
A stage 5 population can be dangerous, as (a) there is a large aging population. (b) there is a large young population. (c) the population has reached its carrying capacity. (d) all of the above
A
Biodiversity refers to (a) the variety of life and its processes. (b) the variety of life and its processes, including the variety of living organisms. (c) the variety of life and its processes, including the variety of living organisms, and the genetic differences among them. (d) the variety of life and its processes, including the variety of living organisms, the genetic differences among them, and the communities and ecosystems in which they occur.
A
Camouflage is (a) an adaptation that evolved through natural selection. (b) a necessary trait for commensalism. (c) part of a well-adapted pioneer species traits. (d) all of the above.
A
Effects of climate change include (a) melting of glaciers and rising sea levels. (b) less droughts and water shortages, due to increased precipitation. (c) decrease in the severity of storms, due to less evaporation. (d) all of the above.
A
How have exotic species affected biodiversity? (a) They have resulted in the extinction of native species. (b) They have resulted in the over-harvesting of fish, trees, and other organisms. (c) They have resulted in global climate change. (d) all of the above
A
Logistic growth (a) is characteristic of populations that do not live under ideal conditions. (b) levels off at the carrying capacity. (c) is characteristic of K-selected species. (d) all of the above
A
Lower death rates in the 1700s resulted from (a) new scientific knowledge of the causes of disease. (b) better use of coal and electricity. (c) the Industrial Revolution. (d) all of the above.
A
The age-sex structure of a quickly growing population would probably have (a) a wide base, showing many young individuals. (b) a wide top, showing many older individuals. (c) a wide middle area, showing many middle-aged individuals. (d) all of the above
A
The best definition for migration is (a) the regular movement of individuals or populations each year during certain seasons. (b) the movement of regular individuals or populations each year during certain seasons. (c) the certain movement of individuals or populations each year during regular seasons. (d) the irregular movement of individuals or populations each year during certain seasons.
A
The carrying capacity of a population (a) is reached as resources become limiting. (b) is reached at the end of exponential growth. (c) is reached in r-selected populations. (d) is reached when the environment begins to be harmed.
A
When organisms must compete for resources, they will usually have a ____________ distribution. (a) uniform (b) random (c) clumped (d) competitive
A
Which of the following is true about a population pyramid? (a) Births add individuals only to the base of the pyramid. (b) Deaths only remove individuals from the top of the pyramid. (c) Births can add individuals to any level of the pyramid, depending on the age of the mother. (d) Births add individuals only to the base of the pyramid, and deaths only remove individuals from the top of the pyramid.
A
Which of the following statements is true about interspecific competition? (1) It occurs between members of different species. (2) It occurs between members of the same species. (3) It often leads to extinction. (4) It is a basic factor in natural selection. (a) 1 and 3 (b) 2 and 4 (c) 1, 3, and 4 (d) 2, 3, and 4
A
Which of the following would NOT be a community? (a) All the plants, insects, and soil in your back yard. (b) All the many varieties of dogs in your neighborhood. (c) All the fish in an aquarium. (d) none of the above
A
Which would lead to specialization (a) When predators of different species compete for the same prey. (b) When two male birds of the same species compete for the same mates. (c) When two male deer fight to lead their herd. (d) all of the above
A
Which would make the best pioneer species during primary succession? (a) bacteria and lichens (b) grasses and birch trees (c) lichens and grasses (d) bacteria, lichens, and grasses
A
Which would represent a population? (a) All the fish in an aquarium. (b) All the dogs in your neighborhood. (c) All the animals in the local zoo. (d) all of the above
A
. A population's age-sex structure influences population growth because (a) older people are more likely to reproduce, while younger people have higher rates of dying. (b) younger people are more likely to reproduce, while older people have higher rates of dying. (c) parents produce relatively few offspring and provide them with a lot of care. (d) in many populations, parents produce moderate numbers of offspring and provide some parental care.
B
. An example of predation is (a) a buffalo eating a lion. (b) a lion eating a buffalo. (c) a buffalo and a lion eating the grass (d) a lion eating a buffalo, and a buffalo eating a zebra
B
. The atmosphere is important, as it (a) refills the oceans with freshwater. (b) provides organisms with gases needed for life. (c) contains oxygen for photosynthesis and carbon dioxide for cellular respiration. (d) all of the above
B
. The carrying capacity (a) occurs at the end of exponential growth. (b) is the largest population size that can be supported without harming the environment. (c) can only be surpassed with significant harm to the population. (d) all of the above.
B
During the time when humans moved from Africa throughout the world, (a) birth and death rates were both fairly low. (b) population growth was slow. (c) there was exponential population growth. (d) the population was close to its carrying capacity.
B
Economic benefits of biodiversity include (a) the prevention of soil erosion. (b) a valuable pool of genetic variation. (c) the natural pollination of flowering plants. (d) all of the above.
B
It is likely that Earth could lose half of its species in the next ____________ years. (a) 50 (b) 100 (c) 500 (d) 1000
B
Population growth can be represented by the equation r = (a) (b + e) - (d + i) (b) (b + i) - (d + e) (c) (b + d) - (i + e) (d) (d + i) - (b + e)
B
Scientists estimate that there may be up to ____________ species alive today. (a) 30 billion (b) 30 million (c) 1.9 million (d) 1.9 billion
B
Scientists have identified about ____________ species alive today. (a) 1.9 billion (b) 1.9 million (c) 5 million (d) 30 million
B
Stage 2 of the demographic transition is represented by (a) slow population growth. (b) fast population growth. (c) a high death rate with fast population growth. (d) a birth rate equal to the death rate, so population growth slows to zero.
B
Stage 2 of the demographic transition is represented by (a) slow population growth. (b) fast population growth. (c) no population growth. (d) high birth and death rates.
B
The carrying capacity for the human population may be about (a) 8 billion people. (b) 9 billion people. (c) 10 billion people. (d) Humans do not have a carrying capacity.
B
The greenhouse effect (a) occurs when gases in the atmosphere direct the sun's heat into the atmosphere. (b) occurs when gases in the atmosphere reflect the sun's heat back down to Earth's surface. (c) occurs when gases in the atmosphere direct extra heat out into the atmosphere. (d) none of the above
B
Which could possibly be a pioneer species during primary succession? (a) the first grass on new soil (b) the first lichen on new rock (c) the first layer of grass in a new park (d) the first trees to grow in a new forest
B
Which is an example of a predator-prey relationship? (a) The relationship between a duck and a pond of water. (b) The relationship between a lion and a zebra. (c) The relationship between a bee and a flower. (d) The relationship between a hen and a rooster.
B
Which is an example of commensalism? (a) The shrimp and the goby fish spending most of their time together. (b) Hermit crabs using the shells of dead snails for homes. (c) The roundworm producing eggs inside its host. (d) Mites getting a "free ride" on larger flying insects.
B
Which of the following are examples of density-dependent factors? (1) food, (2) disease, (3) rainfall, (4) temperature. (a) 1 only (b) 1 and 2 (c) 1, 2, and 3 (d) 1, 2, 3, and 4
B
Which of the following is characteristic of poor countries? (a) A fast population growth due to a high death rate but higher birth rate. (b) A fast population growth due to a high birth rate but falling death rate. (c) A slow population growth due to a low birth rate and falling death rate. (d) A slow population growth due to a low birth rate and low death rate.
B
Which of the following would be an example of population density? (a) 100 caterpillars (b) 100 caterpillars per maple tree (c) 100 caterpillars clumped into 5 specific areas (d) all of the above
B
the variety of life and its processes
Biodiversity
. A random population distribution pattern usually forms (a) among individuals of a species with individuals that live together in groups. (b) among individuals of a species with individuals that compete for a scarce resource. (c) among individuals of a species with individuals who do not strongly interact. (d) none of the above
C
. What is a community? (a) all the individuals of a species in the same area (b) the interactions between the species and non-living aspects of an area (c) all the populations of all the species in the same area (d) all of the above
C
. Which is an example of a predator-prey relationship? (a) The relationship between a bee and a flower. (b) The relationship between a hen and a rooster. (c) The relationship between a lion and a zebra. (d) The relationship between a duck and a pond of water.
C
. Which of the following is a parasite? (a) a praying mantis (b) a zebra (c) a roundworm (d) all of the above
C
. Which two animals have a mutualistic relationship? (a) mites and larger flying insects (b) roundworms and mammals (c) the goby fish and shrimp (d) mosquitoes and humans
C
.Nonrenewable resources include (a) wind and sunlight. (b) metals and other minerals. (c) nuclear power. (d) all of the above.
C
About how long did it take the human population to double in size to 2 billion people? (a) about 20 years (b) about 50 years (c) about 100 years (d) about 200 years
C
An algal bloom forms (a) from a lack of nutrients in the water. (b) from a dead zone. (c) from an excessive growth of algae, killing many other aquatic organisms. (d) all of the above
C
An example of interspecific competition is (a) two male birds competing for the same female. (b) two male lions competing to lead the same pride. (c) two species of big cats competing for the same antelope. (d) all of the above.
C
Currently the human population is exhibiting what type of growth? (a) logistic (b) doubling every 20 years (c) exponential (d) logarithmic
C
During exponential growth, (a) the larger the population becomes, the slower it grows. (b) population growth eventually slows and population size levels off. (c) as population size increases, the growth rate also increases. (d) all of the above
C
During the time when humans moved from Africa throughout the world, (a) birth and death rates were both fairly low. (b) population growth was rapid. (c) population growth was slow. (d) there was no population growth.
C
In what year did the human population reach 1 billion people? (a) 1000 (b) 1700 (c) 1800 (d) 1900
C
The human population is now growing by more than ____________ people a day. (a) 20,000 (b) 100,000 (c) 200,000 (d) 300,000
C
The invention of agriculture (a) led to a decrease in birth rate and death rate. (b) resulted in unreliable food supplies, based on water availability. (c) allowed people to settle down in villages. (d) all of the above
C
. Examples of natural resources include which of the following? (1) ecosystems, (2) biodiversity, (3) fossil fuels, (4) water. (a) 1 and 2 (b) 3 only (c) 3 and 4 (d) 1, 2, 3, and 4
D
. Exponential growth (a) is characteristic of most species under ideal conditions. (b) is a fast growth rate with a large population. (c) begins with a slowly growing population. (d) all of the above
D
. Lower death rates in 17th and 18th century Europe and North America resulted from (a) new scientific knowledge of the causes of disease. (b) better farming techniques. (c) the Industrial Revolution. (d) all of the above
D
. Soil (a) is the foundation of terrestrial ecosystems. (b) is essentially a nonrenewable resource. (c) takes hundreds of millions of years to form. (d) all of the above.
D
. Which is the best definition of a population? (a) The unit of natural selection and evolution. (b) All the species that live in the same area. (c) A group of species that live in the same area. (d) A group of organisms of the same species that live in the same area.
D
A type II survivorship curve (a) has many individuals that live to an old age. (b) has a high death rate in young individuals. (c) has a high death rate in older individuals. (d) shows an even decline in survivors as the population ages.
D
Biodiversity is beneficial to ecosystems in which of the following ways? (a) the natural prevention of soil erosion (b) the natural purification of water in rivers and lakes (c) the natural control of insect pests (d) all of the above
D
Common to all biomes is (are) (a) the primary producers. (b) the way decomposers break down wastes. (c) the basic dependence on sunlight, water, and nutrients. (d) the basic ways species interact.
D
Community interactions include (a) predation. (b) competition. (c) symbiosis. (d) all of the above.
D
Most developed nations are in which stage of the demographic transition? (a) stage 1 (b) stage 2 (c) stage 3 (d) stage 4
D
Population growth can be represented by the equation r = (a) (b + d) - (i + e) (b) (b + e) - (d + i) (c) (d + i) - (b + e) (d) (b + i) - (d + e)
D
Potential solutions in dealing with the world's future population include 201 www.ck12. (a) distributing resources more fairly among all the world's people. (b) using technology to make better use of resources to support more people. (c) changing behaviors to reduce how much humans consume. (d) all of the above.
D
Stage 4 of the demographic transition is represented by (a) a birth rate lower than the death rate, so there is slow population growth. (b) a death rate lower than the birth rate, so there is fast population growth. (c) high birth and death rates, so there is slow population growth. (d) a birth rate equal to the death rate, so population growth slows to zero.
D
The invention of agriculture (a) led to an increased birth rate and death rate. (b) provided a more dependable food supply. (c) allowed people to settle down in villages. (d) all of the above
D
The main difference among the types of symbiotic relationships is (a) how many species either benefit or are harmed. (b) how many species are eaten. (c) how many species are protected. (d) all of the above.
D
What is the biggest cause of extinction today? (a) pollution (b) exotic species (c) global warming (d) habitat loss
D
Which of the following is a parasite? (a) the goby fish (b) the hermit crab (c) the shrimp (d) the roundworm
D
There are two different types of competition:
Intraspecific competition and Interspecific competition
species whose population growth is controlled by density-dependent factors
K-selected
All life relies on a relatively narrow range of ____________, or acidity.
PH
beginning of the sixth mass extinction
Pleistocene
species whose population size is usually well below the carrying capacity
R-Selected
true or false During the 1700s in Europe and North America, new scientific knowledge of the causes of disease led to improved water supplies, sewers, and personal hygiene.
True
Specialization occurs when competing species evolve different ____________.
adaptations
Humans invented ____________ about 10,000 years ago.
agriculture
Dispersal refers to offspring moving ____________ from their parents.
away
Symbiosis is a close relationship between two species in which at least one species ____________.
benefits
____________ refers to the number of species in an ecosystem or the biosphere as a whole.
biodiversity
All ____________ have populations of interacting species.
biomes
Humans have a type ______ survivorship curve, as ________________. (a) II, parents produce moderate numbers of children. (b) III, most of the offspring survive to adulthood so they can reproduce. (c) I, most of the offspring survive to adulthood so they can reproduce. (d) I, parents produce moderate numbers of children.
c
____________ is an adaptation that in prey helps them hide from predators.
camouflage
. The human population may well be close to its ____________ capacity.
carrying
may be 9 billion people for the human population
carrying capacity
the largest population size that can be supported in an area without harming the environment
carrying capacity
a final stable stage
climax community
3 patters of population distribution
clumped, random, uniform
a symbiotic relationship in which one species benefits while the other species is not affected
commensalism
A keystone species is one that plays an especially important role in its ____________.
community
____________ is a relationship between organisms that strive for the same resources in the same place.
competition
The human population is now growing by about 200,000 people a ____________.
day
a four stage model of population growth
demographic transition
Most ____________ nations have entered Stage 4 of the demographic transition.
developed
Population ____________ may be clumped, random, or uniform.
distribution
the change in the numbers and types of species that live in a community over time
ecological succession
Biodiversity generally increases the productivity and stability of ____________.
ecosystems
leaving the population for another area
emmigration
Pollution causes widespread harm to ____________.
enviroment
The population is the unit of natural selection and ____________.
evolution
____________ species may carry disease, prey on native species, and disrupt food webs.
exotic
species that may out-compete native species
exotic species
. The human population has had a pattern of ____________ growth.
exponential
The human population has had a pattern of ___________ growth.
exponential
population growth under ideal conditions
exponential growth
Over 99 percent of all species that ever lived on Earth have gone ____________.
extinct
All biomes, except a desert, have populations of interacting species. True or false
false
K-selected population growth is controlled by density-dependent factors, such as climate. true or false
false
Predation is a relationship in which the prey consumes the predator. true or false
false
true or false A clumped population distribution always has more individuals than a uniform distribution.
false
true or false Plants and algae maintain the atmosphere; during photosynthesis, they add carbon dioxide and remove oxygen.
false
true or false Plants fixing nitrogen and making it available to animals is an important ecological service due to biodiversity.
false
true or false A community is the abiotic part of an ecosystem.
false
true or false A keystone species is one that plays an especially important role in its population.
false
true or false A population consists of all the communities of all the species in the same area.
false
true or false A population's age-sex structure influences population growth, as older people are more likely to reproduce.
false
true or false A stage 5 population has a shrinking population, such as in many poor countries.
false
true or false Evidence shows that the fifth mass extinction is occurring now.
false
true or false Immigration is the regular movement of individuals or populations each year during certain seasons.
false
true or false Interspecific competition occurs between members of the same species.
false
true or false It is possible that in 1000 years, we could lose more than half of Earth's species.
false
true or false Lichens that can live on bare rock may be pioneer species after a flood.
false
true or false Most populations live under ideal conditions, so they grow at exponential rates.
false
true or false Mutualism is a symbiotic relationship in which one species benefits.
false
true or false Nonrenewable resources can be replenished by natural processes as quickly as humans use them.
false
true or false Parasitism is a relationship in which members of one species consume members of another species.
false
true or false Population size is the average number of individuals in a population per unit of area or volume.
false
true or false Populations gain individuals through births and emigration.
false
true or false Stage 1 of the demographic transition has high birth and death rates, which lead to fast population growth.
false
true or false The Industrial Revolution of the 1900s led to new sources of energy
false
true or false The first species to colonize a disturbed area such as this are called primary species.
false
true or false The greenhouse effect is an unnatural feature of Earth's atmosphere - it is caused by humans.
false
true or false The human population has had a pattern of logistic growth.
false
true or false The human population is now growing by about 20,000 people a day.
false
true or false The single biggest cause of extinction today is habitat loss due to forest fires.
false
true or false There are three major types of community interactions: predation, competition, and selection.
false
true or false Today only a few countries remain in Stage 1 of the demographic transition.
false
true or false With a random population distribution, organisms are clustered together in groups.
false
true or false With a type III survivorship curve, parents produce moderate numbers of offspring and provide some parental care.
false
Stage 2: The death rate falls but the birth rate remains high, leading to ____________ population growth.
faster
____________ mass extinctions are recorded in the fossil record.
fifth
valuable benefit of biodiversity found in wild plants and animals
genetic variation
The formula for population ____________ is r = (b + i) - (d + e).
growth
The two main factors affecting population ____________ are the birth rate and death rate.
growth
The single biggest cause of extinction today is ____________ loss.
habitat
single biggest cause of extinction today
habitat loss
The carrying capacity is the ____________ population size that can be supported in an area.
highest
species that is harmed in a symbiotic relationship in which another species benefits
host
The sixth mass extinction is due to ____________ actions.
human
coming into the population from somewhere else
immigration
Under ideal conditions, populations of most species can grow at ____________ rates.
increasing
____________ competition occurs between members of different species.
interspecific
occurs between members of different species
interspecific competition
____________ competition occurs between members of the same species.
intraspecific
occurs between members of the same species
intraspecific competition
a species that plays an especially important role in its community
keystone species
Pioneer species includes ____________ that can live on bare rock.
lichens
Most populations do not live under ideal conditions, so they demonstrate ____________ growth patterns.
logistic
population growth under limiting conditions
logistic growth
the regular movement of individuals or populations each year during certain seasons
migration
a symbiotic relationship in which both species benefit
mutualism
There are three basic types of symbiosis:
mutualism, commensalism, and parasitism.
. Both predators and prey have adaptations to predation that evolve through ____________- selection.
natural
A ____________ resource is something supplied by nature that helps support life.
natural
. Excess ____________ from fertilizer in runoff can cause algal blooms.
nutrients
can result in crowding out other species
overpopulation
. The atmosphere contains ____________ for cellular respiration and carbon dioxide for photosynthesis.
oxygen
species that benefits in a symbiotic relationship in which another species is harmed
parasite
____________ is a relationship in which one species benefits while the other species is harmed.
parasiteism
. The first species to colonize a new area is the ____________ species.
pioneer
the first species to colonize an area that has never before been colonized
pioneer species
. Age-sex structure influences ____________ growth.
population
A ____________ is a group of organisms of the same species that live in the same area.
population
Like weeds, human ____________ are fast growing and disperse rapidly.
population
The age-sex structure influences ____________ growth because usually young individuals reproduce and older individuals die.
population
the average number of individuals in a population per unit of area or volume
population density
how fast a population changes in size over time
population growth rate
diagram that shows the age-sex structure of a population
population pyramid
represents the age-sex structure of a population
population pyramid
There are three major types of community interactions:
predation, competition, and symbiosis.
the species that consumes members of another species
predator
Lions feed on the South African Cape buffalo: the lions are the ____________, and the buffalo are the ____________.
predator , prey
A predator-____________ relationship tends to keep the populations of both species in balance.
prey
the species that is consumed
prey
A glacier retreating is an example of ____________ succession.
primary
Important cases of succession are
primary and secondary succession.
occurs in an area that has never before been colonized
primary succession
natural resources can be classified as
renewable or nonrenewable
The purpose of migration usually is to find food, mates, or other ____________.
resources
occurs in a formerly inhabited area that was disturbed
secondary succession
mass extinction due to human actions
sixth mass extinction
Population ____________ is the number of individuals in a population.
size
Stage 3: The birth rate starts to fall, so population growth starts to ____________.
slow
A community consists of all the populations of all the ____________ in the same area.
species
Species that live in ____________ environments are likely to be K-selected.
stable
high birth and death rates lead to slow population growth
stage 1
the death rate falls but the birth rate remains high, leading to faster population growth
stage 2
the birth rate starts to fall, so population growth starts to slow
stage 3
the birth rate reaches the same low level as the death rate, so population growth slows to zero
stage 4
A ____________ curves represents the number of individuals still alive at each age.
survivorship
graphs that represent the number of individuals still alive at each age
survivorship curve
. ____________ is a close relationship between two species in which at least one species benefits.
symbiosis
. Soil is the foundation of ____________ ecosystems.
terrestrial
. In some areas, because children had to go to school, birth rates fell. true or false
true
Dispersal refers to offspring moving away from their parents. true or false
true
Scientists have identified about 1.9 million species alive today. true or false
true
With a type I survivorship curve, most of the offspring survive to adulthood so they can reproduce. true or false
true
true or faalse Specialization occurs when competing species evolve different adaptations
true
true or false Exotic species introduced by humans into new habitats have resulted in extinction of native species.
true
true or false Global climate change, largely due to the burning of fossil fuels, threatens the existence of many species.
true
true or false Population growth rate is how fast a population changes in size over time.
true
true or false The carrying capacity is the largest population size that can be supported in an area without harming the environment.
true
true or false . All biomes have some species that prey on others for food.
true
true or false . During the 1700s in Europe and North America, better farming techniques and machines increased the food supply.
true
true or false . Nonrenewable resources include fossil fuels such as petroleum, coal, and natural gas.
true
true or false . The total loss of the ozone layer would be devastating to most life.
true
true or false A positive population growth rate means a population is increasing.
true
true or false Acid rain can disrupt protein structure and function.
true
true or false Air pollution is mainly caused by human actions.
true
true or false Biodiversity helps ensure that at least some species will survive major environmental changes.
true
true or false Biodiversity refers to the variety of life and its processes.
true
true or false By 2050, the world's population may be close to its carrying capacity.
true
true or false Camouflage is an adaptation that has evolved through natural selection.
true
true or false Dispersal refers to offspring moving away from their parents.
true
true or false Human populations are fast growing.
true
true or false If a parasite kills its host, the parasite may also die.
true
true or false In some areas, birth rates fell when children were forced to go to school.
true
true or false In stage 3 of the demographic transition, birth rate starts to fall, so population growth starts to slow.
true
true or false In the 1700s, advances in science and technology led to lower death rates in humans.
true
true or false Interspecific competition often leads to extinction, or it may lead to greater specialization.
true
true or false Intraspecific competition leads to the evolution of better adaptations within a species.
true
true or false K-selected population growth is controlled by density-dependent factors.
true
true or false Logistic growth levels out at the carrying capacity.
true
true or false Many of the most important prescription drugs come from wild species.
true
true or false Most species alive today have yet to be identified.
true
true or false Mutualism is a symbiotic relationship in which both species benefit.
true
true or false Of all the water on Earth, only 1 percent is fresh, liquid water.
true
true or false Population growth rate depends on the birth rate, death rate, immigration and emigration.
true
true or false Populations of most species can grow at exponentially at times.
true
true or false Rock that hardens from lava is an example of primary succession.
true
true or false Secondary succession may occur after a forest fire.
true
true or false Some countries are stuck in stage 2 of the demographic transition as their birth rates are still high.
true
true or false Species that live in unstable environments are usually r-selected, and their population size is usually well below the carrying capacity.
true
true or false Stage 5 may be a new stage of the demographic transition, raising issues for some populations
true
true or false The development of agriculture let humans settle down in villages and cities.
true
Many ____________ countries seem to be stuck in Stage 2 of the demographic transition.
undeveloped
Species that live in ____________ environments are likely to r-selected.
unstable
Global ____________ change is raising Earth's air and ocean temperatures.
warming
