Chapter 3 and Chapter 4      REVIEW TEST

 

Modified True/False

Indicate whether the sentence or statement is true or false.  If false, change the identified word or phrase to make the sentence or statement true.

 

____          1.   An ecologist who is studying the relationships among the dominant communities in a geographical region is studying an ecosystem. _________________________

 

____          2.   A biome is a group of ecosystems that have the same climate and dominant communities. _________________________

 

____          3.   Ecologists use tools such as binoculars and microscopes to model changes in the environment. _________________________

 

____          4.   Ecologists can make predictions using ecological models. _________________________

 

____          5.   Producers release carbon dioxide into the atmosphere during the process of photosynthesis. _________________________

 

____          6.   Some autotrophs obtain their energy from hydrogen sulfide to produce carbohydrates. _________________________

 

____          7.   Animals that feed on green plants are called producers. _________________________

 

____          8.   The passage of energy from one organism to another according to a particular feeding sequence is called a food chain. _________________________

 

____          9.   In an ecological pyramid, the biomass of organisms increases at each successive level. _________________________

 

____          10.  Only about 10 percent of the energy in a trophic level is available to organisms at the next trophic level. _________________________

 

____          11.  Only 15 calories are available to a chicken from 1,500 calories of grain. _________________________

 

____          12.  Scientists classify the nitrogen, carbon, and water cycles as biogeochemical cycles. _________________________

 

____          13.  The biosphere cycles less than 1 percent of all the carbon on Earth, even though carbon is the key ingredient in all living systems. _________________________

 

____          14.  Aquatic ecosystems can receive a large input of a limiting nutrient from the runoff from heavily fertilized fields. _________________________

 

____          15.  A lake that is protected from receiving the runoff from a cultivated field is more likely to remain a healthy ecosystem. _________________________

 

____          16.  Earth’s natural “insulating blanket” is the biosphere. _________________________

 

____          17.  The greenhouse effect occurs when carbon dioxide and other gases prevent heat energy from leaving the atmosphere. _________________________

 

____          18.  Carbon dioxide, methane, and water vapor trap light energy. _________________________

 

____          19.  The amount, intensity, and duration of sunlight striking Earth vary with latitude. _________________________

 

____          20.  A symbiotic relationship between organisms in which one species benefits and the other is neither helped nor harmed is mutualism. ______________________________

 

____          21.  An existing community is gradually replaced by another community in an ecological succession. _________________________

 

____          22.  Palm trees and shrubs around a small pool of water in the middle of a barren desert is an example of an ecosystem. _________________________

 

____          23.  The temperate forest biome is typically warmer and has more rainfall than the boreal forest biome. _________________________

 

____          24.  The tropical rain forest is characterized by a wet and a dry season. _________________________

 

____          25.  Tall, perennial grasses and herds of grazing herbivores are inhabitants of the desert biome. ______________________________

 

____          26.  The depth of the water in an aquatic ecosystem determines the amount of oxygen that living things receive there. ____________________

 

____          27.  The single-cell algae that grow in lakes and ponds are zooplankton. ______________________________

 

____          28.  As a flowing-water ecosystem travels downhill from its origin, the water flow typically changes from a turbulent current to slow meanders. _________________________

 

____          29.  The zones of the marine biome are determined by light penetration, distance from shore, and depth. _________________________

 

____          30.  The coastal ocean zone and estuaries are alike in that both are important as breeding and nesting areas for birds. _________________________

 

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

 

____          31.  The branch of biology dealing with interactions among organisms and between organisms and their environment is called

a.

economy.

b.

modeling.

c.

recycling.

d.

ecology.

 

 

____          32.  The part of Earth in which all living things exist is called the

a.

biome.

b.

community.

c.

ecosystem.

d.

biosphere.

 

 

____          33.  All of the members of a particular species that live in one area are called a(an)

a.

biome.

b.

population.

c.

community.

d.

ecosystem.

 

 

____          34.  Which of the following descriptions about the organization of an ecosystem is correct?

a.

Communities make up species, which make up populations.

b.

Populations make up species, which make up communities.

c.

Species make up communities, which make up populations.

d.

Species make up populations, which make up communities.

 

 

____          35.  The simplest grouping of more than one kind of organism in the biosphere is

a.

a population.

b.

a community.

c.

an ecosystem.

d.

a species.

 

 

____          36.  The lowest level of environmental complexity that includes living and nonliving factors is the

a.

biome.

b.

community.

c.

ecosystem.

d.

biosphere.

 

 

____          37.  Which of the following methods is NOT used by ecologists to study the living world?

a.

experimenting

b.

classifying

c.

modeling

d.

observing

 

 

____          38.  Which ecological inquiry method is an ecologist using when he or she enters an area periodically to count the population numbers of a certain species?

a.

questioning

b.

observing

c.

experimenting

d.

modeling

 

 

____          39.  A mathematical formula designed to predict population fluctuations in a community could be called a(an)

a.

biological experiment.

b.

biological system.

c.

ecological model.

d.

ecological observation.

 

 

____          40.  Green plants are

a.

producers.

b.

consumers.

c.

herbivores.

d.

omnivores.

 

 

____          41.  What is the original source of almost all the energy in most ecosystems?

a.

carbohydrates

b.

sunlight

c.

water

d.

carbon

 

 

 

Figure 3-1

 

____          42.  The algae at the beginning of the food chain in Figure 3-1 are

a.

consumers.

b.

decomposers.

c.

producers.

d.

heterotrophs.

 

 

____          43.  An organism that produces its own food supply from inorganic compounds is called a(an)

a.

heterotroph.

b.

consumer.

c.

detritivore.

d.

autotroph.

 

 

____          44.  Which of the following organisms does NOT require sunlight to live?

a.

chemosynthetic bacteria

b.

algae

c.

trees

d.

photosynthetic bacteria

 

 

____          45.  An organism that cannot make its own food is called a(an)

a.

heterotroph.

b.

chemotroph.

c.

autotroph.

d.

producer.

 

 

____          46.  In which way are green plants in a sunny mountain meadow and sulfur bacteria in a deep-sea volcanic vent alike?

a.

They both use photosynthesis to make their own food.

b.

They both produce carbohydrates and oxygen.

c.

They both use chemosynthesis to produce their own food.

d.

They both produce carbon and hydrogen.

 

 

____          47.  Organisms that break down and feed on wastes and dead organisms are called

a.

decomposers.

b.

omnivores.

c.

autotrophs.

d.

producers.

 

 

____          48.  What is an organism that feeds only on plants called?

a.

carnivore

b.

herbivore

c.

omnivore

d.

detritivore

 

 

____          49.  All the interconnected feeding relationships in an ecosystem make up a food

a.

interaction.

b.

chain.

c.

network.

d.

web.

 

 

____          50.  The total amount of tissue of all the organisms in a food chain is called the

a.

organic mass.

b.

trophic mass.

c.

energy mass.

d.

biomass.

 

 

____          51.  What is an ecological model of the relationships that form a network of complex interactions among organisms in a community from producers to decomposers?

a.

food web

b.

an ecosystem

c.

food chain

d.

a population

 

 

____          52.  What animals eat both producers and consumers?

a.

herbivores

b.

omnivores

c.

chemotrophs

d.

autotrophs

 

 

____          53.  What is the term for each step in the transfer of energy and matter within a biological community?

a.

energy path

b.

food web

c.

trophic level

d.

food pyramid

 

 

____          54.  A bird stalks, kills, and then eats an insect. Based on its behavior, which ecological terms describe the bird?

a.

herbivore, decomposer

b.

producer, heterotroph

c.

carnivore, consumer

d.

autotroph, herbivore

 

 

____          55.  A snake that eats a frog that has eaten an insect that fed on a plant is a

a.

first-level producer.

b.

first-level consumer.

c.

second-level producer.

d.

third-level consumer.

 

 

 

Figure 3-2

 

____          56.  Figure 3-2 illustrates a(an)

a.

biomass pyramid.

b.

food pyramid.

c.

numbers pyramid.

d.

energy pyramid.

 

 

____          57.  In which way does Figure 3-2 differ from a typical model of trophic levels?

a.

Second-level consumers outnumber first-level consumers.

b.

Third-level consumers outnumber second-level consumers.

c.

First-level consumers outnumber producers.

d.

First-level consumers outnumber second-level consumers.

 

 

____          58.  Only 10 percent of the energy stored in an organism can be passed on to the next trophic level. Of the remaining energy, some is used for the organism’s life processes, and the rest is

a.

used in reproduction.

b.

stored as body tissue.

c.

stored as fat.

d.

eliminated as heat.

 

 

____          59.  Most of the energy available to a consumer trophic level is used by organisms for

a.

transfer to the next trophic level.

b.

respiration, movement, and reproduction.

c.

producing inorganic chemical compounds.

d.

performing photosynthesis.

 

 

____          60.  Which type of pyramid shows the amount of living tissue at each trophic level in an ecosystem?

a.

a numbers pyramid

b.

an energy pyramid

c.

a biomass pyramid

d.

a food pyramid

 

 

____          61.  Matter can recycle through the biosphere because

a.

matter is passed out of the body as waste.

b.

matter is assembled into chemical compounds.

c.

biological systems do not use up matter, they transform it.

d.

biological systems use only carbon, oxygen, hydrogen, and nitrogen.

 

 

____          62.  The repeated movement of water between Earth’s surface and the atmosphere is called

a.

the water cycle.

b.

the condensation cycle.

c.

precipitation.

d.

evaporation.

 

 

____          63.  Which of the following is NOT recycled in the biosphere?

a.

water

b.

nitrogen

c.

carbon

d.

energy

 

 

____          64.  What is the process by which organisms convert nitrogen gas in the air to ammonia?

a.

nitrogen fixation

b.

excretion

c.

decomposition

d.

denitrification

 

 

____          65.  Which energy-rich compound is formed from organic matter by mixed biogeochemical processes?

a.

calcium carbonate

b.

petroleum

c.

carbohydrate

d.

atmospheric nitrogen

 

 

____          66.  How is carbon stored in the biosphere?

a.

in the atmosphere as carbon dioxide

b.

underground as fossil fuels and calcium carbonate rock

c.

in the oceans as dissolved carbon dioxide

d.

all of the above

 

 

____          67.  Nitrogen fixation is carried out primarily by

a.

humans.

b.

plants.

c.

bacteria.

d.

ammonia.

 

 

____          68.  Which of the following has a direct role in the nitrogen cycle?

a.

bacteria

b.

legumes

c.

decomposers

d.

all of the above

 

 

____          69.  Organisms need nutrients in order to

a.

utilize hydrogen and oxygen.

b.

carry out essential life functions.

c.

recycle chemical compounds.

d.

carry out nitrogen fixation.

 

 

____          70.  The movements of energy and nutrients through living systems are different because

a.

energy flows in one direction and nutrients recycle.

b.

energy is limited in the biosphere and nutrients are always available.

c.

nutrients flow in one direction and energy recycles.

d.

energy forms chemical compounds and nutrients are lost as heat.

 

 

____          71.  Biogeochemical cycling ensures that

a.

human activity will have no effect on them.

b.

cells well not become limited in any one nutrient.

c.

nutrients will not become scarce in any part of the biosphere.

d.

many nutrients will not reach toxic concentrations in the biosphere.

 

 

____          72.  The event that can occur after a lake receives a large input of a limiting nutrient is

a.

an algal bloom.

b.

algae begin to die and decomposers take over.

c.

nitrogen compounds are recycled.

d.

the concentration of oxygen drops below the necessary level.

 

 

____          73.  The rate at which organic matter is created by producers in an ecosystem is called

a.

a limiting nutrient.

b.

fertilization.

c.

an algal bloom.

d.

primary productivity.

 

 

____          74.  Which is most likely to be a limiting nutrient in a freshwater pond?

a.

phosphorus

b.

nitrogen

c.

carbon

d.

potassium

 

 

____          75.  If a nutrient is in such short supply in an ecosystem that it affects an animal's growth, the

a.

animal becomes a decomposer.

b.

substance is a limiting nutrient.

c.

nutrient leaves the food chain.

d.

ecosystem will not survive.

 

 

____          76.  The average year-after-year conditions of temperature and precipitation in a particular region is the region’s

a.

weather.

b.

latitude.

c.

ecosystem.

d.

climate.

 

 

____          77.  The Earth’s climate is, in part, created by the interplay of

a.

temperatures, ecosystems, and wind.

b.

landmasses, the atmosphere, and the ocean.

c.

weather, heat transport, and the environment.

d.

solar radiation, surface temperatures, and biomes.

 

 

____          78.  Climate is a global factor that produces

a.

Earth’s unique ocean and atmosphere.

b.

the shape and elevation of landmasses.

c.

a wide range of environmental conditions that shapes communities.

d.

solar energy within the atmosphere.

 

 

____          79.  Temperatures on Earth remain within a suitable range for life as we know it because of the

a.

unequal heating of Earth’s surface.

b.

loss of heat to space.

c.

radiation of sunlight back into the atmosphere.

d.

greenhouse effect.

 

 

____          80.  The loss of heat to space is slowed by

a.

radiation entering the atmosphere.

b.

atmospheric gases.

c.

solar energy.

d.

the biosphere.

 

 

____          81.  The greenhouse effect is

a.

the result of an excess of carbon dioxide in the atmosphere.

b.

a natural phenomenon that maintains Earth’s temperature range.

c.

the result of the differences in the angle of the sun’s rays.

d.

an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere.

 

 

____          82.  Earth has three main climate zones because of the differences in latitude and

a.

amount of solar energy received.

b.

angle of heating.

c.

ocean currents.

d.

prevailing winds.

 

 

____          83.  Cool air over the poles will

a.

rise.

b.

sink.

c.

absorb heat from the equator.

d.

flow parallel to Earth’s surface.

 

 

____          84.  The unequal heating of Earth’s surface

a.

drives wind and ocean currents.

b.

causes winds that transport heat throughout the biosphere.

c.

has important effects on Earth’s climate regions.

d.

all of the above

 

 

____          85.  The tendency for warm air to rise and cool air to sink results in

a.

global wind patterns.

b.

ocean upwelling.

c.

unequal heat distribution.

d.

regional precipitation.

 

 

____          86.  A mountain can affect climate by

a.

absorbing more solar energy at the peak than at the base of the mountain.

b.

causing precipitation to fall mostly on one side of the mountain.

c.

pushing a cool air mass back out over the ocean.

d.

interfering with air currents and affecting Earth’s rotation.

 

 

____          87.  Why does Earth have three main climate zones?

a.

Warm air rises at the equator and cold air sinks over the poles causing an unequal distribution of heat over Earth.

b.

There are differences in latitude and, thus, the angle of heating from the sun.

c.

Continents and other landmasses physically interfere with global heat distribution.

d.

The Earth rotates and affects the major ocean currents.

 

 

____          88.  Each of the following is an abiotic factor in the environment EXCEPT

a.

plant life.

b.

soil type.

c.

rainfall.

d.

temperature.

 

 

____          89.  Which is a biotic factor that affects the size of a population in a specific ecosystem?

a.

average temperature of the ecosystem

b.

type of soil in the ecosystem

c.

number and kinds of predators in the ecosystem

d.

concentration of oxygen in the ecosystem

 

 

____          90.  During a long period when there is no rainfall, a mountain lion may temporarily leave its usual hunting territory to drink from a farm pond. This behavior is probably due to

a.

its need to find different foods to eat.

b.

the change in an abiotic factor in its environment.

c.

its need to find a new habitat.

d.

the change in a biotic factor in its environment.

 

 

____          91.  An organism’s niche is

a.

the way the organism uses the range of physical and biological conditions in which it lives.

b.

all the physical and biological factors in the organism’s environment.

c.

the range of temperatures that the organism needs to survive.

d.

a full description of the place an organism lives.

 

 

____          92.  Several species of warblers can live in the same spruce tree ONLY because they

a.

have different habitats within the tree.

b.

eat different foods within the tree.

c.

occupy different niches within the tree.

d.

can find different temperatures within the tree.

 

 

____          93.  An interaction in which one organism captures and feeds on another organism is called

a.

competition.

b.

sybiosis.

c.

mutualism.

d.

predation.

 

 

____          94.  Different species can share the same habitat, but competition among them is reduced if they

a.

reproduce at different times.

b.

eat less.

c.

move away.

d.

occupy different niches.

 

 

____          95.  No two species can occupy the same niche in the same habitat at the same time

a.

because of the interactions that shape the ecosystem.

b.

unless the species require different abiotic factors.

c.

because of the competitive exclusion principle.

d.

unless the species require different biotic factors.

 

 

____          96.  A symbiosis in which both species benefit is

a.

commensalism.

b.

mutualism.

c.

predation.

d.

parasitism.

 

 

____          97.  The symbiotic relationship between a flower and the insect that feeds on its nectar is an example of

a.

mutualism because the flower provides the insect with food, and the insect pollinates the flower.

b.

parasitism because the insect lives off the nectar from the flower.

c.

commensalism because the insect doesn’t harm the flower and the flower doesn’t benefit from the relationship.

d.

predation because the insect feeds on the flower.

 

 

____          98.  A predator can increase the numbers of certain species in its habitat by

a.

killing and eating the competitors of other species.

b.

living symbiotically with other species.

c.

avoiding certain prey species.

d.

crowding out the species it does not eat.

 

 

____          99.  The series of predictable changes that occurs in a community over time is called

a.

population growth.

b.

ecological succession.

c.

climax community.

d.

climate change.

 

 

____          100.            Primary succession can begin after

a.

a forest fire.

b.

a lava flow.

c.

farm land is abandoned.

d.

a severe storm.

 

 

____          101.            What is one difference between primary and secondary succession?

a.

Primary succession is slow and secondary succession is rapid.

b.

Secondary succession begins on soil and primary succession begins on newly exposed surfaces.

c.

Primary succession modifies the environment and secondary succession does not.

d.

Secondary succession begins with lichens and primary succession begins with trees.

 

 

____          102.            Which factor can influence continual change in an ecosystem?

a.

further disturbances

b.

long-term climate changes

c.

introduction of nonnative species

d.

all of the above

 

 

____          103.            Which of the following occurs during the ecological succession of an ecosystem?

a.

An ecosystem reaches a final, unchanging stage.

b.

Changes occur that are caused by organisms outside the ecosystem.

c.

Living organisms modify their environment a little at a time.

d.

Parts of communities split off to form new communities.

 

 

____          104.            Which is a factor that could interrupt the progress of succession?

a.

colonization of surfaces by lichens

b.

different animals appearing at each stage

c.

another natural disturbance

d.

long-term fluctuations in climate

 

 

____          105.            Climate conditions that differ significantly from the climate of the surrounding area are called

a.

natural features.

b.

microclimates.

c.

biomes.

d.

ecosystems.

 

 

____          106.            An example of a place with a microclimate is

a.

a mountain range capped with ice.

b.

a forested park in a desert city.

c.

an orchid growing in a rain forest.

d.

coniferous trees in a temperate forest.

 

 

____          107.            Which of the following can influence the climate in a small area within a biome?

a.

the average temperature and precipitation

b.

the latitude of the biome

c.

natural features such as a lake

d.

the greenhouse effect

 

 

____          108.            Which biome is characterized by very low temperatures, little precipitation, and permafrost?

a.

desert

b.

temperate forest

c.

tundra

d.

tropical dry forest

 

 

____          109.            Which two biomes have the least amount of precipitation?

a.

tropical rain forest and temperate forest

b.

tropical savanna and tropical dry forest

c.

tundra and desert

d.

boreal forest and temperate woodland and shrubland

 

 

____          110.            A biome is identified by its particular set of abiotic factors and its

a.

average precipitation and temperature.

b.

characteristic ecological community.

c.

distance from the equator.

d.

specific geographical location.

 

 

____          111.            Which animal would be found in the biome that has cold to moderate winters, warm summers, fertile soils, and is home to a variety of vegetation, such as coniferous trees, broadleaf deciduous trees, flowering shrubs, and ferns?

a.

white-tailed deer

b.

polar bear

c.

iguana

d.

moose

 

 

____          112.            Aquatic ecosystems are classified by all of the following EXCEPT

a.

depth of the water.

b.

flow of the water.

c.

temperature of the water.

d.

chemistry of the water.

 

 

____          113.            The chemistry of aquatic ecosystems is determined by the

a.

amount of salts, nutrients, and oxygen dissolved in the water.

b.

the number of other organisms present in the water.

c.

amount of rainfall the water receives.

d.

biotic and abiotic factors in the water.

 

 

____          114.            Which one of the following statements is NOT true of freshwater wetlands?

a.

Freshwater wetlands include bogs, marshes, and swamps.

b.

Unlike marshes, swamps have trees and shrubs.

c.

The water in freshwater wetlands is brackish.

d.

Wetlands are important breeding grounds for migratory birds.

 

 

____          115.            Ponds and lakes are

a.

flowing-water ecosystems.

b.

wetlands.

c.

standing-water ecosystems.

d.

estuaries.

 

 

____          116.            Which is NOT an adaptation that organisms have for living in flowing water?

a.

hooks

b.

plankton

c.

streamlined bodies

d.

suckers

 

 

____          117.            Which is one way a wetland ecosystem differs from a standing-water ecosystem?

a.

Water circulates in a standing-water ecosystem, but not in a wetland.

b.

Wetlands are nesting areas for birds, but standing-water ecosystems are not.

c.

Water does not always cover a wetland as it does a standing-water ecosystem are not.

d.

Wetlands are salty, but standing-water ecosystems are fresh.

 

 

____          118.            The photic zone

a.

extends to the bottom of the open ocean.

b.

extends to a depth of about 200 meters.

c.

is deep, cold, and permanently dark.

d.

is where chemosynthetic bacteria are the producers.

 

 

____          119.            Which of the following statements is NOT true about the oceanic zone?

a.

The open ocean has very low levels of nutrients.

b.

Organisms in the deep oceanic zone are exposed to frigid temperatures and total darkness.

c.

The oceanic zone begins at the low-tide mark and extends to the end of the continental shelf.

d.

Most of the photosynthesis activity on Earth occurs in the open ocean.

 

 

____          120.            Which organism lives where it is routinely exposed to air, heat, battering waves, strong currents, and is often submerged?

a.

sea stars

b.

tube worms

c.

dolphins

d.

whales

 

 

Completion

Complete each sentence or statement.

 

                  121.            The study of interactions among organisms and between organisms and their physical surroundings is called ____________________.

 

 

Figure 3-3

 

                  122.            Ecologists make ____________________ to study large-scale phenomena, such as Earth’s water cycle shown in Figure 3-3.

 

                  123.            In the water cycle shown in Figure 3-3, the process of _________________________ occurs between evaporation and precipitation.

 

                  124.            The water shown flowing over land in Figure 3-3 is called ____________________.

 

                  125.            The use of radio tags, satellites, and microscopes are all techniques employed in the basic ecological research method of ____________________.

 

                  126.            Without a constant input of ____________________, living systems cannot function.

 

                  127.            Plant-eating animals such as cows are called ____________________.

 

                  128.            Organisms that break down organic matter and return it to the environment are called ____________________.

 

 

Figure 3-1

 

                  129.            Of the organisms represented in Figure 3-1, the organisms in the oceans with the smallest total biomass are most likely the ____________________.

 

                  130.            The organisms in the greatest numbers in Figure 3-1 are the ____________________.

 

                  131.            In a four-level energy pyramid, if the first level contains 500 calories of energy, the third level will contain approximately ____________________ calories.

 

                  132.            Ground water, when taken up by the roots of plants, eventually reenters the atmosphere by the process of _________________________.

 

                  133.            The chemical substances that an organism requires to live are called ____________________.

 

                  134.            Living organisms require nitrogen to make ____________________, which are used to build proteins.

 

                  135.            Phosphorus is a key ingredient of ____________________ because farmers know that it forms part of the energy-producing molecules that plants require in order to grow.

 

                  136.            The energy of incoming ____________________ drives Earth’s weather and helps to determine climate.

 

                  137.            Weather differs from ____________________ in that weather can change on a daily basis and is not considered a description of year-to-year conditions of temperature and precipitation.

 

                  138.            Solar radiation is to warmth as climate is to ____________________.

 

                  139.            Atmospheric gases that trap heat inside Earth’s atmosphere are called ____________________ gases.

 

 

Figure 4-1

 

                  140.            According to Figure 4-1, the north polar zone lies above ____________________ latitude.

 

                  141.            As shown in Figure 4-1, the climate zone that receives the most direct sunlight throughout the year lies between ____________________ and ____________________ latitudes.

 

                  142.            Organisms within an ecosystem are ____________________ factors in that ecosystem.

 

                  143.            Over time, some plants growing in an area are crowded out by other plants. The new plants use up water and nutrients needed by the previous plants. The disappearance of the first plants is due to ______________________________.

 

                  144.            A small city park that is sunnier and windier than the climate of the surrounding areas has it own _________________________.

 

                  145.            Giant redwood trees are at home in the ______________________________ biome.

 

                  146.            An aquatic environment’s water ____________________ refers to the amount of dissolved salts, nutrients, and oxygen in the water.

 

                  147.            The abiotic factor used to determine the climate of an area that has the least effect on aquatic ecosystems is ____________________.

 

                  148.            A swamp is different from a lake as a freshwater ecosystem because a swamp is a ____________________ ecosystem.

 

                  149.            Photosynthesis is limited to the well-lit upper layer of the ocean, which scientists refer to as the ____________________ zone.

 

                  150.            A coral reef is formed by the hard, ________________________ skeletons of coral animals.

 

Short Answer

 

                  151.            What and where is the biosphere?

 

                  152.            Explain the ecological significance of interdependence.

 

 

Figure 3-1

 

                  153.            Using Figure 3-1, explain the relationship between sharks and the sun.

 

                  154.            Identify each of the organisms in Figure 3-1 according to their roles in the food chain.

 

                  155.            Compare and contrast the two main types of producers.

 

                  156.            Describe the flow of energy between the following members of an ecosystem: decomposers, autotrophs, heterotrophs, and the sun.

 

                  157.            Why are decomposers the final consumers in every food chain?

 

                  158.            Consider a food web in which snakes eat mice; toads eat beetles; owls eat mice and toads; eagles eat rabbits, snakes, and owls; cougars eat deer; and foxes eat rabbits and mice. What animal occupies (gets energy in) more than one trophic level? Explain.

 

 

Figure 3-2

 

                  159.            Describe the flow of energy to the owl in Figure 3-2 if the tree provides 1,500 calories of energy to the insects.

 

                  160.            What is the most likely explanation for why Figure 3-2 shows only one organism at its base? In what way would an energy diagram be different?

 

                  161.            Compare the movement of energy in the biosphere with the movement of matter through the biosphere.

 

 

Figure 3-3

 

                  162.            Using Figure 3-3, trace the path of water that leaves a lake through evaporation, and describe how it might return to the lake.

 

                  163.            Explain how seepage and transpiration in Figure 3-3 are related.

 

                  164.            Explain how the biogeochemical cycling of oxygen, carbon, nitrogen, and hydrogen are important to living systems.

 

                  165.            What events typically contribute to an algal bloom in a lake or ocean?

 

                  166.            List five factors that contribute to global climate patterns.

 

                  167.            How are atmospheric gases like the glass in a greenhouse?

 

                  168.            What are greenhouse gases?

 

 

Figure 4-1

 

                  169.            Using Figure 4-1, describe a climate you might find at 10°N latitude.

 

                  170.            Using Figure 4-1, explain why average temperatures decrease with increasing distance from the equator.

 

                  171.            Describe at least two parts of the niche of a bullfrog.

 

                  172.            List three biotic and three abiotic factors that determine the survival of a rabbit in a temperate forest.

 

                  173.            How is mutualism similar to and different from commensalism?

 

                  174.            What is an ecological resource?

 

                  175.            Explain why plants do not participate in the succession of a whale-fall community as they do in land-ecosystem succession.

 

                  176.            Describe an important role that pioneer species play in primary succession.

 

                  177.            Deserts vary greatly depending on elevation and latitude. What characteristic do all deserts share?

 

                  178.            What are the three main factors that govern aquatic ecosystems?

 

                  179.            Why are hooks and suckers not typically found in organisms inhabiting standing-water ecosystems?

 

                  180.            What criteria are used for determining ocean zones?

 

Essay

 

                  181.            Explain how ecological models are used by ecologists.

 

                  182.            Describe the two sources of energy that fuel life on Earth.

 

                  183.            How does a food web differ from a food chain?

 

                  184.            Describe the flow of energy from the sun through living systems. How do each of the organisms in the energy flow relate to the sun?

 

                  185.            Describe the three types of ecological pyramids.

 

                  186.            Describe the roles of bacteria in the nitrogen cycle.

 

                  187.            How might a large input of phosphorus affect a freshwater lake over time?

 

                  188.            Would you receive more energy from corn by eating it directly or by eating the same mass of beef from a cow that had been fed on corn? Explain your reasoning.

 

                  189.            Describe the biological significance of the carbon cycle. Where is carbon found in the biosphere?

 

                  190.            A farmer harvests a crop of corn from a large field. He then plants beans, which are legumes, in that same field. Once the beans are growing well, the farmer plows them back into the soil to decay. What would be the advantage of plowing the bean plants back into the soil?

 

                  191.            Explain how ocean currents originate and affect Earth’s climates.

 

                  192.            Describe the greenhouse effect and explain how it maintains Earth’s temperature range.

 

                  193.            Predict how the tropical rain forest and desert biomes would change if Earth were 30°C cooler than it is today. What phenomenon keeps this from happening?

 

                  194.            Describe Earth’s main climate zones and explain how latitude affects these climate zones.

 

                  195.            Name and define the three main classes of symbiotic relationships. Give examples of each.

 

                  196.            Describe the stages of primary succession in land environments, including lichens, mosses, grasses, shrubs, and trees.

 

                  197.            What is a microclimate? Give an example.

 

                  198.            Explain why there are no tall trees in the tundra biome. What are some of the biotic and abiotic phenomena that exist in the tundra?

 

                  199.            Why does a flowing-water ecosystem support little plant life at its source? Describe how the ecosystem changes to support organisms as it flows.

 

                  200.            List the six main zones of the marine biome. Explain how these zones are differentiated.

 

Other

 

USING SCIENCE SKILLS

 

 

Figure 3-4

 

                  201.            Applying Concepts How do ecologists use diagrams such as Figure 3-4 to study ecological relationships?

 

                  202.            Inferring Figure 3-4 shows a food web arranged into trophic levels. How many energy-transferring steps away from the sun is the wolf? How do you know?

 

                  203.            Inferring A food web, such as the one in Figure 3-4, is a model of the feeding relationships in an ecosystem. What makes this model representative of an ecosystem?

 

                  204.            Interpreting Graphics In Figure 3-4, how many first-level consumers are there for each producer?

 

                  205.            Comparing and Contrasting In Figure 3-4, compare the amount of energy available to the wolf if it eats a rabbit with the amount of energy available to the wolf if it eats a shrew.

 

USING SCIENCE SKILLS

 

 

 

Figure 3-5

 

                  206.            Predicting How might a large omnivore change the flow of energy in Figure 3-5, Diagram II?

 

                  207.            Inferring If a limiting nutrient is supplied to the producers in Figure 3-5, Diagram II, what effect could it have on the birds?

 

                  208.            Interpreting Graphics How many Kilocalories (Kcal) can the top carnivore in Figure 3-5, Diagram I store? Explain.

 

                  209.            Applying Concepts What three scientific approaches do ecologists use to explain complex relationships, such as in the energy pyramid in Figure 3-5?

 

                  210.            Applying Concepts Describe how chemosynthesis could contribute to the energy represented by Figure 3-5, Diagram I?

 

USING SCIENCE SKILLS

 

 

Figure 3-6

 

                  211.            Using Models At which level of ecological organization does the carbon cycle shown in Figure 3-6 function? Explain.

 

                  212.            Applying Concepts What is the diagram represented by Figure 3-6 called by ecologists? What is its advantage to scientific inquiry?

 

                  213.            Interpreting Graphics Which steps in Figure 3-6 show the carbon cycle passing through living systems?

 

                  214.            Comparing and Contrasting Compare the carbon cycle shown in Figure 3-6 with what you know about photosynthesis and respiration. What simple change could be made to the figure to show how the carbon cycle and the oxygen cycle are related?

 

                  215.            Applying Concepts Explain how Figure 3-6 relates to plant productivity.

 

USING SCIENCE SKILLS

 

Average Rainfall and Temperature of the Earth's Biomes

Biome

Average Yearly Rainfall

Average Temperatures

Climate Zone

Tropical Rain Forest

400 cm

Daytime: 34ºC

Nighttime: 20ºC

Tropical

Tropical Dry Forest

250–300 cm

Dry season: 32ºC

Wet season: 20ºC

Tropical

Temperate Forest

75–125 cm

Summer: 28ºC

Winter: 6ºC

Mostly temperate

Boreal Forest

35–75 cm

Summer: 14ºC

Winter: –10ºC

Mostly temperate

Tropical Savanna

150 cm

Dry season: 34ºC

Wet season: 16ºC

Mostly tropical

Desert

Less than 25 cm

Summer: 38ºC

Winter: 7ºC

Tropical and temperate

Temperate Grassland

25–75 cm

Summer: 30ºC

Winter: 0ºC

Temperate

Tropical Woodland

and Scrubland

Less than 50 cm

Summer: 20ºC

Winter: 10ºC

Temperate

Tundra

30–50 cm

Daytime: 12ºC

Winter: –26ºC

Temperate and polar

 

Figure 4-2

 

                  216.            Comparing and Contrasting In Figure 4-2, compare the average daytime temperature of the tropical rain forest with the average summer temperature of the tundra. How can you account for the difference?

 

                  217.            Calculating What is the highest average temperature shown in Figure 4-2? the lowest average temperature? How many degrees of temperature are there between the highest and the lowest temperatures? What global phenomenon maintains this range between climates?

 

                  218.            Using Tables and Graphs Which climate zone includes the most biomes listed in Figure 4-2?

 

                  219.            Using Tables and Graphs Which biomes listed in Figure 4-2 include areas that have an average yearly rainfall of less than 75 cm? Which biomes include areas that have an average yearly rainfall of more than 200 cm?

 

                  220.            Analyzing Data Which two biomes show in Figure 4-2 have seasons determined by the amount of precipitation they receive at different times of the year?

 

USING SCIENCE SKILLS

 

 

Figure 4-3

 

                  221.            Applying Concepts Describe some of the biotic and abiotic factors you might find at point A and in region B of Figure 4-3.

 

                  222.            Interpreting Graphics The boreal forest and river valley depicted in Figure 4-3 were swept by fire 20 years ago. The forest on the hills on each side of the river valley were destroyed. Does this illustration show an earlier or later stage of succession? Which kind of succession has taken place? Explain what will happen in this ecosystem if there are no more disturbances.

 

                  223.            Predicting Examine Figure 4-3. Predict what might happen to this flowing-water ecosystem in a boreal forest biome if a dam were built on the river in region C.

 

                  224.            Inferring Which regions of the river in Figure 4-3 contain more nutrients than the other regions? Explain.

 

                  225.            Comparing and Contrasting Compare and contrast region E in Figure 4-3 with region D. Describe the physical characteristics of each region.

 

USING SCIENCE SKILLS

 

Some Organisms of the Marine Biome

Intertidal

Coastal

Oceanic Zone

Zone

Ocean Zone

Photic Zone

Aphotic Zone

Algae

Coral

Diving birds

Angler fish

Anemone

Dolphins

Dolphins

Deep-sea octopus

Barnacles

Jellyfish

Herring

Hatchet fish

Birds:

Kelp

Jellyfish

Krill

Gull

Lobsters

Marlin

Lantern fish

Herons

Otters

Penguins

Sea cucumbers

Plovers

Plankton

Plankton

Sponges

Terns

Sailfish

Salmon

Squids

Clams

Sea stars

Sea snakes

Hydrothermal Vent

Crustaceans

Sea urchins

Sea turtles

Chemosynthetic

Mollusks

Seals

Sharks

bacteria

Mussels

Sharks

Shrimp

Clams

Sea urchins

Small fish

Swordfish

Crabs and other

Seaweed

Snails

Tuna

crustaceans

Snails

Whales

Whales

Tube worms

 

Figure 4-4

 

                  226.            Comparing and Contrasting Contrast the abiotic factors at high tide with those at low tide for the organisms in the table, Intertidal Zone, Figure 4-4.

 

                  227.            Inferring From the table in Figure 4-4, select at least three organisms from the Coastal Ocean Zone and describe how they might interact.

 

                  228.            Using Models Figure 4-4 shows an event that is taking place at about 2000 meters on the ocean floor. Identify the event, the zones where it is happening, and its importance to the marine biome.

 

                  229.            Interpreting Graphics Using Figure 4-4, describe energy availability in the oceanic zone at a depth of 6000 meters and at 150 meters.

 

                  230.            Analyzing Data From the table in Figure 4-4, which of the organisms from any column can also be listed in the photic zone column? Justify your answer.


Chapter 3 and Chapter 4      REVIEW TEST

Answer Section

 

MODIFIED TRUE/FALSE

 

            1.    F, a biome           

 

            2.    T                        

 

            3.    F, observe           

 

            4.    T                        

 

            5.    F, oxygen            

 

            6.    T                        

 

            7.    F, consumers                            

 

            8.    T                        

 

            9.    F, decreases                             

 

            10.  T                        

 

            11.  F, 150                 

 

            12.  T                        

 

            13.  T                        

 

            14.  T                        

 

            15.  T                        

 

            16.  F, atmosphere                           

 

            17.  T                        

 

            18.  F, heat                

 

            19.  T                        

 

            20.  F, commensalism                       

 

            21.  T                        

 

            22.  F, microclimate                         

 

            23.  T                        

 

            24.  F, dry                 

 

            25.  F, tropical savanna                               

 

            26.  F, light                

 

            27.  F, phytoplankton                        

 

            28.  T                        

 

            29.  T                        

 

            30.  F, Wetlands                              

 

MULTIPLE CHOICE

 

            31.  D

 

            32.  D

 

            33.  B

 

            34.  D

 

            35.  B

 

            36.  C

 

            37.  B

 

            38.  B

 

            39.  C

 

            40.  A

 

            41.  B

 

            42.  C

 

            43.  D

 

            44.  A

 

            45.  A

 

            46.  B

 

            47.  A

 

            48.  B

 

            49.  D

 

            50.  D

 

            51.  A

 

            52.  B

 

            53.  C

 

            54.  C

 

            55.  D

 

            56.  C

 

            57.  C

 

            58.  D

 

            59.  B

 

            60.  C

 

            61.  C

 

            62.  A

 

            63.  D

 

            64.  A

 

            65.  B

 

            66.  D

 

            67.  C

 

            68.  D

 

            69.  B

 

            70.  A

 

            71.  D

 

            72.  A

 

            73.  D

 

            74.  A

 

            75.  B

 

            76.  D

 

            77.  B

 

            78.  C

 

            79.  D

 

            80.  B

 

            81.  B

 

            82.  B

 

            83.  B

 

            84.  D

 

            85.  A

 

            86.  B

 

            87.  B

 

            88.  A

 

            89.  C

 

            90.  B

 

            91.  A

 

            92.  C

 

            93.  D

 

            94.  D

 

            95.  C

 

            96.  B

 

            97.  A

 

            98.  A

 

            99.  B

 

            100.                B

 

            101.                B

 

            102.                D

 

            103.                C

 

            104.                C

 

            105.                B

 

            106.                B

 

            107.                C

 

            108.                C

 

            109.                C

 

            110.                B

 

            111.                A

 

            112.                C

 

            113.                A

 

            114.                C

 

            115.                C

 

            116.                B

 

            117.                C

 

            118.                B

 

            119.                C

 

            120.                A

 

COMPLETION

 

                  121.            ecology

 

                  122.            models

predictions

 

                  123.            condensation

 

                  124.            runoff

 

                  125.            observing

 

                  126.            energy

 

                  127.            herbivores

consumers

 

                  128.            decomposers

detritivores

 

                  129.            sharks

 

                  130.            algae

 

                  131.            5

 

                  132.            transpiration

 

                  133.            nutrients

 

                  134.            amino acids

 

                  135.            fertilizers

 

                  136.            sunlight

 

                  137.            climate

 

                  138.            weather

 

                  139.            greenhouse

 

                  140.            66.5°N

 

                  141.            23.5°N, 23.5°S

 

                  142.            biotic

 

                  143.            competitive exclusion

 

                  144.            microclimate

 

                  145.            northwest coniferous forest

 

                  146.            chemistry

 

                  147.            rainfall

precipitation

 

                  148.            wetland

 

                  149.            photic

 

                  150.            calcium carbonate

 

SHORT ANSWER

 

                  151.            The biosphere is the combined portions of the planet in which all of life exists, including land, air, and water. It extends from about 8 kilometers above Earth’s surface to about 11 kilometers below the surface of the ocean.

 

                  152.            Organisms interact with each other and their environments. These interactions produce a web of interdependence among individual organisms, species, populations, communities, and the environments in which they live at every level of organization in the biosphere.

 

                  153.            Sharks are the top carnivore in a food chain that begins with algae. Algae are producers that get their energy from the sun.

 

                  154.            The algae are autotrophs, the producers at the base of the food chain. The remaining organisms are heterotrophs that depend on other organisms for energy. Zooplankton are first-level consumers, the herbivores. Small fishes are second-level consumers, squids are third-level consumers, and sharks are fourth-level consumers. Sharks are also the top carnivores.

 

                  155.            One type of producers are plants, algae, and certain bacteria that produce their own food by photosynthesis. Another type of producers are bacteria that use chemicals to produce their own food by the process of chemosynthesis. The two producers are alike because they both produce carbohydrates and oxygen. They are different because they get their energy from different sources.

 

                  156.            Energy flows from the sun to the autotrophs, and from the autotrophs to the heterotrophs. Energy also flows from the autotrophs and the heterotrophs to the decomposers.

 

                  157.            In time, all living things die regardless of where they are in the food chain. The decomposers break down the remains of dead plants and animals, releasing substances that are reused by other organisms in the ecosystem.

 

                  158.            The eagle is a consumer at the third trophic level when it eats a rabbit, and a consumer at the fourth trophic level when it eats a snake or an owl.

 

                  159.            The insects would provide 10 percent (one-tenth) of 1,500 calories, or 150 calories, of energy to the shrews. The shrews would provide one-tenth of 150 calories, or 15 calories to the owl.

 

                  160.            The tree at the base has much more available energy than all the insects that live in it. An energy diagram would be broad at the base like a typical pyramid.

 

                  161.            Energy flows in one direction from the sun to producers and consumers. Matter moves in biogeochemical cycles through living systems, the Earth, the atmosphere, and the oceans.

 

                  162.            Water evaporates from the lake, condenses in the atmosphere, and falls as precipitation. Some rain may fall directly on the lake and some water may return to the lake as runoff.

 

                  163.            Water seeps through soil and into the ground water. Roots of trees and plants take the water up through their roots. Plants release the water through the process of transpiration. Both seepage and transpiration are parts of the water cycle.

 

  164.          The cycling of oxygen, carbon, nitrogen, and hydrogen make these materials available to living organisms in a form that cells can use. These materials make up over 95 percent of the body tissues of most organisms.

 

                  165.            A large input of a limiting nutrient, such as nitrogen or phosphorus, can cause the algae to grow and reproduce more quickly. If there are not enough consumers to eat the excess algae, the algae will grow to cover the surface of the water.

 

                  166.            Five factors are: the trapping of heat by the atmosphere, latitude, the transport of heat by winds and ocean currents, precipitation, the shape and elevation of landmasses

 

                  167.            Glass traps heat energy inside the greenhouse. Atmospheric gases trap heat energy inside Earth’s atmosphere.

 

                  168.            Greenhouse gases are atmospheric gases, such as carbon dioxide, methane, and water vapor that trap heat energy.

 

                  169.            The climate at 10°N latitude is most likely a hot, rainy climate, because this location is in the tropical zone.

 

                  170.            Figure 4-1 shows the curvature of Earth. The sun’s rays strike Earth at increasingly lower angles with increasing distance from the equator, thus providing less and less direct sunlight.

 

                  171.            A bullfrog’s niche includes living in or near ponds, lakes, and slow-moving streams; burrowing into mud to hibernate; and the female laying eggs in water during the warmer months.

 

                  172.            Biotic factors may include: plants the rabbit eats, predators that eat the rabbit, and other competitive species. Abiotic factors include: temperature, rainfall, and space.

 

                  173.            They are both symbiotic relationships. In mutualism, both species benefit from the relationship; in commensalism, only one species benefits while the other is neither helped nor harmed.

 

                  174.            An ecological resource is any necessity of life for an organism, such as water, nutrients, light, food, or space.

 

                  175.            Whale-fall succession takes place on the deep, permanently dark ocean floor where there is no light for photosynthesis and no plants can grow.

 

                  176.            In primary succession, pioneer plants such as lichens help rocks to break up in the process of soil formation. They also contribute organic material to the forming soil in which plants can grow.

 

                  177.            A desert biome is defined as having less than 25 cm of annual rainfall.

 

                  178.            Aquatic ecosystems are determined by the depth, flow, and chemistry of the overlying water.

 

                  179.            Hooks and suckers are adaptations for holding on in moving water, and are common in organisms that inhabit flowing-water ecosystems.

 

                  180.            The vertical ocean zones are determined by the distance from shore and the depth of the water. The horizontal zones are determined by how far light penetrates the water.

 

ESSAY

 

                  181.            Ecologists use models to gain insight into complex phenomena, such as the effects of global warming. Many ecological models consist of mathematical formulas based on data collected through observation and experimentation. The predictions made by such models are often tested by further observations and experiments.

 

                  182.            Sunlight is the main energy source for life on Earth. Only 0.1 percent of all the sun’s energy that reaches Earth is used by living things. Inorganic chemical compounds also provide energy for life on Earth. Plants, some algae, and certain bacteria can capture energy from sunlight or chemicals and use that energy to produce food.

 

                  183.            A food chain is a series of steps in which organisms transfer energy by eating and being eaten. A food web is a feeding relationship that forms a network of complex interactions. A food web links all the food chains in an ecosystem together.

 

                  184.            Producers that rely on photosynthesis, such as plants and algae, use energy from the sun to produce and store food. Organisms, such as herbivores, eat those producers to obtain the energy they need for their life processes. In turn, other consumers will eat those organisms. Each organism in this flow of energy can be assigned to a trophic level. Producers make up the first trophic level. Herbivores comprise the second trophic level. In the third and successive trophic levels are the consumers that eat other consumers. All organisms in each trophic level are the same number of energy-transferring steps away from the sun.

 

                  185.            An energy pyramid is a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or web. A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem. A pyramid of numbers shows the relative number of organisms at each trophic level.

 

                  186.            Certain types of bacteria are able to use nitrogen gas directly. These bacteria, which live in the soil and on the roots of legumes, convert nitrogen gas to ammonia during the process of nitrogen fixation. Ammonia is a form of nitrogen that is readily taken up by producers. Other bacteria in the soil convert ammonia into nitrates and nitrites, which are also taken up directly by producers. Still other soil bacteria convert nitrates into nitrogen gas during the process of nitrification, returning the nitrogen to the atmosphere.

 

                  187.            The growth of producers in a water environment like a lake are slowed by a lack of a limiting nutrient. Phosphorus is a limiting nutrient in most freshwater environments. If phosphorus is added in large amounts, such as from runoff from heavily fertilized fields, an immediate rise in the amount of producers like algae can occur. This result is called a bloom. If an algal bloom in a lake gets too extensive, it may cover the surface of the water.

 

                  188.            You would receive more energy by eating corn directly. As a rule, approximately 10 percent of the energy at a given trophic level is transferred to organisms at the next trophic level. Therefore, at each successive trophic level, less and less energy is available to an organism. Thus, by eating an animal that has fed on corn, you will receive less energy than if you had eaten that same corn directly.

 

                  189.            Carbon is biologically significant because it is the key ingredient of all living organisms. Carbon is found in several reservoirs within the biosphere. In addition to being in living cells, carbon occurs in the air as carbon dioxide gas, in the oceans as dissolved carbon dioxide, and in rocks, soil, and under ground as coal, petroleum, and calcium carbonate rock.

 

                  190.            Legumes are plants that have nodules on their roots containing nitrogen-fixing bacteria. If a farmer plants beans in a field after corn is harvested, the bacteria will fix nitrogen gas from the atmosphere and release it into the soil making the field richer in nitrogen. If the farmer plows the plants back into the soil, the plants will add the nitrogen from decomposing plant tissues back into the soil. In this way, the farmer will have to use less commercial fertilizer to grow corn in that same field later.

 

                  191.            Cold, salty water near the poles sinks and then flows parallel to the ocean bottom, eventually rising again in warmer regions through a process call upwelling. Meanwhile, surface water is moved by winds. In both cases, the water flow creates ocean currents. Like air currents, ocean currents transport heat energy within the biosphere. Surface ocean currents warm or cool the air above them, thus affecting the weather and climate of nearby landmasses.

 

                  192.            Solar energy has an important effect on the temperature of the atmosphere.  Atmospheric gases, such as carbon dioxide, methane, and water vapor, do not allow heat energy to pass out of the atmosphere. This natural situation in which heat is retained by these greenhouse gases is called the greenhouse effect. This effect provides a natural insulating blanket around Earth and maintains its temperature range.

 

                  193.            The tropical rain forest biome would seldom, if ever, rise above freezing temperatures and would not support life as we know it now. Desert biomes would only briefly rise above freezing temperatures during the summer and would probably more closely resemble the tundra biome as it is today. The Earth’s greenhouse effect prevents this from happening by trapping heat energy, which keeps the planet warm, and maintains Earth’s present temperature range.

 

                  194.            Because Earth is a sphere that is tilted on its axis, different parts of its surface receive varying amounts of solar radiation. As a result of differences in latitude and thus the angle of heating, Earth has three main climate zones. At the equator, the sun’s rays are most direct so the climate is almost always warm in the tropical zone. In the temperate zone, the climate ranges from hot to cold depending on the season. The polar zones receive the sun’s rays at the lowest angle and are always cold. Climates become generally cooler and drier with increasing distance from the equator.

 

                  195.            The three main classes of symbiotic relationships are mutualism, commensalism, and parasitism. In mutualism, both species benefit from the relationship. For example, flowers depend on certain insects to pollinate them. The flowers provide the insects with food in the form of nectar, pollen, or other substances. In commensalism, one member of the association benefits and the other is neither helped nor harmed. Barnacles attached to the skin of whales benefit from food particles in the water moving past the swimming whale, but the whale is not affected. In parasitism, one member benefits by obtaining all its nutritional needs from the host. The host can be damaged, but is usually not killed. Fleas, ticks, and lice are examples of parasites that live on the bodies of mammals.

 

                  196.            Primary succession occurs on newly exposed surfaces, such as a fresh lava flow that destroys the previous ecosystem. The first organisms to appear are plantlike lichens that colonize the newly formed volcanic surfaces. Over several years, various species of plants establish themselves among the rocks, including mosses and grasses, which take root in the thin layer of soil. Eventually, tree seedlings and shrubs sprout among the plant community. A characteristic ecological community may eventually dominate the area.

 

                  197.            Mountains, forests, oceans, lakes, and other natural features can influence the climate in a small area within a biome. The climate within such a small area often differs significantly from the climate of the surrounding area and is called a microclimate. An example of a microclimate is the redwood forests on parts of California’s northern coast. Some areas a short distance inland from these forests are desertlike, inhabited by cacti and other drought-resistant plants.

 

                  198.            Summers are not long enough or warm enough to thaw the soil so that tall plants like trees can grow roots. Cold temperatures, high winds, and permafrost limit plant height. The tundra is characterized by ground-hugging plants such as lichens, mosses, and short grasses due to the short growing season and the long, cold, and dark winters. Migratory birds, caribou, and small rodents are some of the animals that inhabit the tundra.

 

                  199.            A freshwater ecosystem is turbulent where it springs from its source so few plants can become established. Organisms with adaptations for living in swift water, such as fish with streamlined bodies and catfish with suckers to anchor themselves to the rocks, thrive there. As the water flows, it picks up sediments. Where sediments build up, plants are able to establish themselves. The water flows more slowly downstream and the plants and animals grow more diverse to include turtles, beavers, and river otters.

 

                  200.            The main zones of the marine biome are the photic zone, the aphotic zone, the intertidal zone, the coastal ocean zone, the open ocean zone, and the benthic zone. The horizontal zones include the photic zone, which is the well-lit upper layer where photosynthesis takes place. Below the photic zone is the aphotic zone, which is permanently dark. Another more-or-less horizontal zone is the benthic zone. This zone extends along the ocean floor from the coastal ocean through the ocean zones. The vertical zones include the intertidal zone, which is the area most affected by tides. The coastal ocean zone extends from the low-tide mark to the end of the continental shelf. The open ocean, or oceanic zone, begins at the edge of the continental shelf and extends outward. This is the largest marine zone, covering over 90 percent of the surface area of the world’s oceans.

 

OTHER

 

                  201.            The diagram is a model based on observations and experiments. Ecologists use models to explain phenomena and make predictions.

 

                  202.            The wolf is on the fourth trophic level, so it is four steps away from the sun.

 

                  203.            An ecosystem is a collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment. A food web represents relationships among all the organisms and their environment.

 

                  204.            There is one first-level consumer for corn, three for carrots, four for flowering shrubs, and one for trees.

 

                  205.            The rabbit is on the second trophic level and has more energy available to the wolf than the shrew on the third trophic level.

 

                  206.            Possible answer: A large omnivore would consume energy at every trophic level, reducing the amount of energy available to each level above the producers.

 

                  207.            The producers are the bluegrass. Adding a limiting nutrient to the grass would increase the amount of primary productivity. The result would be an increased amount of biomass at the producer level, and increasing biomass and available energy at each successive level. The number of birds could increase, because there would be more for them to eat.

 

                  208.            The bass is the top carnivore. It has 100 Kcal available to it from the trophic level below it. The bass will use part of that energy for its life processes, lose some as heat, and will be able to store only about 10 percent, or 10 Kcal.

 

                  209.            observing, experimenting, and modeling

 

                  210.            Certain bacteria are chemosynthetic autotrophs and live in the sediments of some aquatic ecosystems where no light is available. They are producers that use inorganic molecules to produce food. The energy they produce would add to the total amount produced by plants to supply energy to the ecosystem.

 

                  211.            The carbon cycle completes a biogeochemical cycle through every level of ecological organization throughout the biosphere.

 

                  212.            Figure 3-6 is a model of the carbon cycle. Ecologists use models to explain phenomena too large or too complex to study in nature. The carbon cycle occupies the entire biosphere so it is an advantage to scientists to use a model to study the carbon cycle. Using a model makes the entire phenomenon observable.

 

                  213.            The carbon cycle passes through living systems in the processes of respiration, photosynthesis, and decomposition.

 

                  214.            Figure 3-6 shows carbon dioxide being taken up by plants. Oxygen is released during photosynthesis. Oxygen is taken up by living cells and carbon dioxide is released during respiration. To show how oxygen cycles, the arrows leading to and from photosynthesis and respiration could simply be reversed.

 

                  215.            Figure 3-6 shows plants taking up carbon dioxide during photosynthesis. Plants use carbon dioxide and the energy in sunlight to manufacture carbohydrates.

 

                  216.            The tropical rain forest has an average daytime temperature of 34°C. The tundra has an average summer temperature of 12°C. The difference is that the tropical rain forest receives almost direct sunlight all year long. The tundra receives sunlight at a much lower angle, resulting in a colder climate than the tropical rain forest has.

 

                  217.            highest temperature = 38°C; lowest temperature = –26°C

range = 38 Celsius degrees above zero + 26 Celsius degrees below zero = 64 degrees

The greenhouse effect is responsible for maintaining Earth’s range of temperatures.

 

                  218.            temperate zone

 

                  219.            Biomes that have less than 75 cm of yearly rainfall include: temperate forest, boreal forest, desert, temperate grassland, temperate woodland and shrubland, and tundra. Biomes that have more than 200 cm of yearly rainfall include: tropical rain forest and tropical dry forest.

 

                  220.            The tropical dry forest and the tropical savanna each have a wet season and a dry season.

 

                  221.            Point A is the origin of this flowing-water ecosystem. The water is most likely turbulent and cold. Region B would have swiftly moving water, which would be turbulent where it goes over the waterfall. There would be little plant life in the water due to the turbulence, and the animals in the water would have adaptations to keep themselves from being swept away.

 

                  222.            The hills show a growth of shrubs and a few small trees. This indicates a later stage of secondary succession. Eventually, an ecologically characteristic boreal forest will grow if there are no more disturbances.

 

                  223.            A lake would form above the dam, creating a standing-water ecosystem. Without a flow of water, the river below the dam would dry up. The dry land would then undergo secondary succession, and because of the climate and latitude, would eventually have the ecological characteristics of a land biome, a boreal forest.

 

                  224.            Regions D and E would contain more nutrients because the water is moving very slowly and more plants can grow. It can support algae and bacteria and many more organisms than farther up the mountain where they would be washed away in the current. The river also carries nutrient-rich sediments from higher up the mountain down to regions D and E.

 

                  225.            Sample answer: In region D, the water is moving slowly and meandering across the land. In region E, the sediments carried by the water have formed a marsh where the flow is moving gradually toward a lake. The regions are different in that the water is moving faster in region D than in region E, and region E likely has more numbers and kinds of organisms. They are alike in that they are both part of the same aquatic ecosystem.

 

                  226.            At high tide, sea water is an abiotic factor because the intertidal organisms are submerged. At low tide, the abiotic factors are exposure to air, sunlight, heat, battering waves, and strong currents.

 

                  227.            Sample answer: Kelp and the algae in plankton are producers and are food for many of the organisms in the coastal ocean zone. Large fishes such as sailfish and sharks, and mammals such as dolphins, eat the small fishes. Benthos, such as snails, sea urchins, sea stars, and lobsters compete for resources on the ocean floor.

 

                  228.            Whale-fall succession is occurring at 1500 meters in the aphotic, benthic, and open ocean zones. Whale-fall succession supports several communities over time, and increases diversity in the whale-fall area.

 

                  229.            At 6000 meters, in the area of the hydrothermal vent, chemosynthetic bacteria are the producers, providing energy for organisms that inhabit the area. Other benthos feed on dead organic materials that drift down from the surface. At 150 meters, algae are the producers because this is within the photic zone. Complex food webs exist in this upper area of the ocean.

 

                  230.            All of the organisms listed in the intertidal zone can be listed in the photic zone column. This zone is always in the photic zone. Also, all of the organisms listed in the coastal ocean zone can be listed in the photic zone because the coastal ocean zone is almost always in the photic zone. Some species of clams, crabs, and tube worms could also be listed in the photic zone. Generally, only those organisms listed in the aphotic zone and chemosynthetic bacteria would not be found in the photic zone.