chapter 12 biology

There are three major types of community interactions:

There are two different types of competition:

There are three basic types of symbiosis:

Important cases of succession are

3 patters of population distribution

natural resources can be classified as

All biomes, except a desert, have populations of interacting species.
True or false

true or false
Camouflage is an adaptation that has evolved through natural selection.

Predation is a relationship in which the prey consumes the predator.
true or false

true or false
Interspecific competition occurs between members of the same species.

true or false
Interspecific competition often leads to extinction, or it may lead to greater specialization.

true or false
A keystone species is one that plays an especially important role in its population.

true or false
Rock that hardens from lava is an example of primary succession.

true or false
Mutualism is a symbiotic relationship in which both species benefit.

true or false
The first species to colonize a disturbed area such as this are called primary species.

true or false
If a parasite kills its host, the parasite may also die.

true or false
Intraspecific competition leads to the evolution of better adaptations within a species.

true or false
Secondary succession may occur after a forest fire.

true or false
A population consists of all the communities of all the species in the same area.

true or false
There are three major types of community interactions: predation, competition, and selection.

true or false
Lichens that can live on bare rock may be pioneer species after a flood.

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

Community interactions include
(a) predation.
(b) competition.
(c) symbiosis.
(d) all of the above.

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.

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.

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.

Which of the following is a parasite?
(a) the goby fish
(b) the hermit crab
(c) the shrimp
(d) the roundworm

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

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 species that plays an especially important role in its community

a symbiotic relationship in which both species benefit

a final stable stage

occurs in an area that has never before been colonized

the species that consumes members of another species

a symbiotic relationship in which one species benefits while the other species is not affected

the species that is consumed

the first species to colonize an area that has never before been colonized

the change in the numbers and types of species that live in a community over time

species that benefits in a symbiotic relationship in which another species is harmed

occurs in a formerly inhabited area that was disturbed

occurs between members of the same species

species that is harmed in a symbiotic relationship in which another species benefits

occurs between members of different species

A glacier retreating is an example of ____________ succession.

____________ is a relationship in which one species benefits while the other species is harmed.

Lions feed on the South African Cape buffalo: the lions are the ____________, and the buffalo
are the ____________.

Symbiosis is a close relationship between two species in which at least one species ____________.

Specialization occurs when competing species evolve different ____________.

____________ is a relationship between organisms that strive for the same resources in the same
place.

Pioneer species includes ____________ that can live on bare rock.

A keystone species is one that plays an especially important role in its ____________.

____________ is an adaptation that in prey helps them hide from predators.

____________ competition occurs between members of different species.

A community consists of all the populations of all the ____________ in the same area.

All ____________ have populations of interacting species.

true or false
A clumped population distribution always has more individuals than a uniform distribution.

true or false
Population growth rate is how fast a population changes in size over time.

true or false
A population’s age-sex structure influences population growth, as older people are more likely
to reproduce.

Dispersal refers to offspring moving away from their parents.
true or false

With a type I survivorship curve, most of the offspring survive to adulthood so they can
reproduce.
true or false

true or false
Populations gain individuals through births and emigration.

true or false
Logistic growth levels out at the carrying capacity.

true or false
K-selected population growth is controlled by density-dependent factors.

true or false
Most populations live under ideal conditions, so they grow at exponential rates.

true or false
Immigration is the regular movement of individuals or populations each year during certain
seasons.

true or false
The carrying capacity is the largest population size that can be supported in an area without
harming the environment.

true or false
With a type III survivorship curve, parents produce moderate numbers of offspring and
provide some parental care.

true or false
With a random population distribution, organisms are clustered together in groups.

true or false
A positive population growth rate means a population is increasing.

true or false
Species that live in unstable environments are usually r-selected, and their population size is
usually well below the carrying capacity.

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

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

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.

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)

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

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.

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

When organisms must compete for resources, they will usually have a ____________ distribution.
(a) uniform
(b) random
(c) clumped
(d) competitive

represents the age-sex structure of a population

coming into the population from somewhere else

population growth under limiting conditions

the average number of individuals in a population per unit of area or volume

species whose population size is usually well below the carrying capacity

leaving the population for another area

the largest population size that can be supported in an area without harming the environment

graphs that represent the number of individuals still alive at each age

population growth under ideal conditions

how fast a population changes in size over time

species whose population growth is controlled by density-dependent factors

the regular movement of individuals or populations each year during certain seasons

The population is the unit of natural selection and ____________.

The purpose of migration usually is to find food, mates, or other ____________.

Species that live in ____________ environments are likely to be K-selected.

Population ____________ may be clumped, random, or uniform.

The carrying capacity is the ____________ population size that can be supported in an area.

A ____________ curves represents the number of individuals still alive at each age.

The two main factors affecting population ____________ are the birth rate and death rate.

The age-sex structure influences ____________ growth because usually young individuals reproduce
and older individuals die.

Under ideal conditions, populations of most species can grow at ____________ rates.

Population ____________ is the number of individuals in a population.

The formula for population ____________ is r = (b + i) – (d + e).

Species that live in ____________ environments are likely to r-selected.

Dispersal refers to offspring moving ____________ from their parents.

A ____________ is a group of organisms of the same species that live in the same area.

true or false
Human populations are fast growing.

true or false
Stage 5 may be a new stage of the demographic transition, raising issues for some populations

true or false
The human population has had a pattern of logistic growth.

true or false
The development of agriculture let humans settle down in villages and cities.

true or false
In the 1700s, advances in science and technology led to lower death rates in humans.

true or false
The human population is now growing by about 20,000 people a day.

true or false
Today only a few countries remain in Stage 1 of the demographic transition.

true or false
Stage 1 of the demographic transition has high birth and death rates, which lead to fast
population growth.

true or false
In stage 3 of the demographic transition, birth rate starts to fall, so population growth starts
to slow.

true or false
Some countries are stuck in stage 2 of the demographic transition as their birth rates are still
high.

true or false
By 2050, the world’s population may be close to its carrying capacity.

true or false
In some areas, birth rates fell when children were forced to go to school.

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.

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

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.

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.

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

Most developed nations are in which stage of the demographic transition?
(a) stage 1
(b) stage 2
(c) stage 3
(d) stage 4

The human population is now growing by more than ____________ people a day.
(a) 20,000
(b) 100,000
(c) 200,000
(d) 300,000

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.

the birth rate starts to fall, so population growth starts to slow

the death rate falls but the birth rate remains high, leading to faster population growth

may be 9 billion people for the human population

diagram that shows the age-sex structure of a population

high birth and death rates lead to slow population growth

the birth rate reaches the same low level as the death rate, so population growth slows to zero

a four stage model of population growth

Stage 3: The birth rate starts to fall, so population growth starts to ____________.

The human population has had a pattern of ___________ growth.

Most ____________ nations have entered Stage 4 of the demographic transition.

Today, no country remains in Stage ____________ of the demographic transition.

Homo sapiens arose only about ____________ years ago in Africa.

Stage ____________: High birth and death rates lead to slow population growth.

Stage 4: The birth rate reaches the same low level as the death rate, so population growth slows to
____________.

The human population is now growing by about 200,000 people a ____________.

Many ____________ countries seem to be stuck in Stage 2 of the demographic transition.

Stage 2: The death rate falls but the birth rate remains high, leading to ____________ population
growth.

Humans invented ____________ about 10,000 years ago.

Like weeds, human ____________ are fast growing and disperse rapidly.

true or false
Biodiversity refers to the variety of life and its processes.

Scientists have identified about 1.9 million species alive today.
true or false

true or false
Many of the most important prescription drugs come from wild species.

true or false
Biodiversity helps ensure that at least some species will survive major environmental changes.

true or false
Plants and algae maintain the atmosphere; during photosynthesis, they add carbon dioxide
and remove oxygen.

true or false
Evidence shows that the fifth mass extinction is occurring now.

true or false
It is possible that in 1000 years, we could lose more than half of Earth’s species.

true or false
The single biggest cause of extinction today is habitat loss due to forest fires.

true or false
Global climate change, largely due to the burning of fossil fuels, threatens the existence of
many species.

true or false
Exotic species introduced by humans into new habitats have resulted in extinction of native
species.

true or false
Plants fixing nitrogen and making it available to animals is an important ecological service
due to biodiversity.

true or false
Most species alive today have yet to be identified.

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.

Scientists have identified about ____________ species alive today.
(a) 1.9 billion
(b) 1.9 million
(c) 5 million
(d) 30 million

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.

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

What is the biggest cause of extinction today?
(a) pollution
(b) exotic species
(c) global warming
(d) habitat loss

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

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

It is likely that Earth could lose half of its species in the next ____________ years.
(a) 50
(b) 100
(c) 500
(d) 1000

the variety of life and its processes

species that may out-compete native species

valuable benefit of biodiversity found in wild plants and animals

mass extinction due to human actions

identified species alive today

beginning of the sixth mass extinction

single biggest cause of extinction today

can result in crowding out other species

The single biggest cause of extinction today is ____________ loss.

Biodiversity generally increases the productivity and stability of ____________.

Scientists have identified about ____________ million species alive today.

____________ mass extinctions are recorded in the fossil record.

The sixth mass extinction is due to ____________ actions.

____________ species may carry disease, prey on native species, and disrupt food webs.

Over 99 percent of all species that ever lived on Earth have gone ____________.

____________ refers to the number of species in an ecosystem or the biosphere as a whole.

Global ____________ change is raising Earth’s air and ocean temperatures.

Pollution causes widespread harm to ____________.

. 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

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

. 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

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.

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

. 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

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.

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

. 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

. Which of the following is a parasite?
(a) a praying mantis
(b) a zebra
(c) a roundworm
(d) all of the above

. 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.

true or false
A community is the abiotic part of an ecosystem.

true or false
. All biomes have some species that prey on others for food.

true or false
Parasitism is a relationship in which members of one species consume members of another
species.

true or faalse
Specialization occurs when competing species evolve different adaptations

true or false
Mutualism is a symbiotic relationship in which one species benefits.

A predator-____________ relationship tends to keep the populations of both species in balance.

. Both predators and prey have adaptations to predation that evolve through ____________-
selection.

. The first species to colonize a new area is the ____________ species.

. ____________ is a close relationship between two species in which at least one species benefits.

____________ competition occurs between members of the same species.

. 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.

. 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

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

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 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.

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)

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.

. 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

. 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.

. 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.

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 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.

true or false
Population growth rate depends on the birth rate, death rate, immigration and emigration.

true or false
Population size is the average number of individuals in a population per unit of area or
volume.

true or false
Dispersal refers to offspring moving away from their parents.

true or false
Populations of most species can grow at exponentially at times.

K-selected population growth is controlled by density-dependent factors, such as climate.
true or false

. Age-sex structure influences ____________ growth.

Most populations do not live under ideal conditions, so they demonstrate ____________ growth
patterns.

In what year did the human population reach 1 billion people?
(a) 1000
(b) 1700
(c) 1800
(d) 1900

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

Currently the human population is exhibiting what type of growth?
(a) logistic
(b) doubling every 20 years
(c) exponential
(d) logarithmic

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.

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.

Most developed nations are in which stage of the demographic transition?
(a) stage 1
(b) stage 2
(c) stage 3
(d) stage 4

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.

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.

. 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

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.

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

. 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

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 or false
. During the 1700s in Europe and North America, better farming techniques and machines
increased the food supply.

true or false
The Industrial Revolution of the 1900s led to new sources of energy

. In some areas, because children had to go to school, birth rates fell.
true or false

true or false
A stage 5 population has a shrinking population, such as in many poor countries.

. The human population has had a pattern of ____________ growth.

The human population is now growing by more than ____________ people a day.

. The human population may well be close to its ____________ capacity.

.Nonrenewable resources include
(a) wind and sunlight.
(b) metals and other minerals.
(c) nuclear power.
(d) all of the above.

. Renewable resources include
(a) wind and sunlight.
(b) fossil fuels.
(c) nuclear power.
(d) all of the above.

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

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

. 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.

. 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.

. 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.

. 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

. 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

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.

true or false
Air pollution is mainly caused by human actions.

true or false
Acid rain can disrupt protein structure and function.

true or false
Nonrenewable resources can be replenished by natural processes as quickly as humans use
them.

true or false
The greenhouse effect is an unnatural feature of Earth’s atmosphere – it is caused by
humans.

true or false
. The total loss of the ozone layer would be devastating to most life.

true or false
Of all the water on Earth, only 1 percent is fresh, liquid water.

true or false
. Nonrenewable resources include fossil fuels such as petroleum, coal, and natural gas.

A ____________ resource is something supplied by nature that helps support life.

. Soil is the foundation of ____________ ecosystems.

. Excess ____________ from fertilizer in runoff can cause algal blooms.

. The atmosphere contains ____________ for cellular respiration and carbon dioxide for photosynthesis.

All life relies on a relatively narrow range of ____________, or acidity.