2The branch of biology dealing with interactions among organisms and between organisms and their environment is calledeconomy.modeling.recycling.ecology.
3The combined portions of Earth in which all living things exist is called the biome.community.ecosystem.biosphere.
4All of the members of a particular species that live in one area are called a(an) biome.population.community.ecosystem.
5Which of the following descriptions about the organization of an ecosystem is correct? Communities make up species, which make up populations.Populations make up species, which make up communities.Species make up communities, which make up populations.Species make up populations, which make up communities.
6The simplest grouping of more than one kind of organism in the biosphere is a population.a community.an ecosystem.a species.
7The lowest level of environmental complexity that includes living and nonliving factors is the biome.community.ecosystem.biosphere.
8Which of the following is NOT a basic method used by ecologists to study the living world? experimentingclassifyingmodelingobserving
9questioning observing experimenting modeling 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?questioningobservingexperimentingmodeling
10A mathematical formula designed to predict population fluctuations in a community could be called a(an)biological experiment.biological system.ecological model.ecological observation.
12What is the original source of almost all the energy in most ecosystems? carbohydratessunlightwatercarbon
13The algae at the beginning of the food chain in the figure are consumers.decomposers.producers.heterotrophs.
14An organism that uses energy to produce its own food supply from inorganic compounds is called a(an) heterotroph.consumer.detritivore.autotroph.
15Which of the following organisms does NOT require sunlight to live? chemosynthetic bacteriaalgaetreesphotosynthetic bacteria
16An organism that cannot make its own food is called a(an) heterotroph.chemotroph.autotroph.producer.
17In which way are plants in a sunny mountain meadow and sulfur bacteria in a deep-sea volcanic vent alike?They both use photosynthesis to make their own food.They both produce carbohydrates and oxygen.They both use chemosynthesis to produce their own food.They both produce carbon and hydrogen.
18Organisms that obtain nutrients by breaking down dead and decaying plants and animals are called decomposers.omnivores.autotrophs.producers.
19What is an organism that feeds only on plants called? carnivoreherbivoreomnivoredetritivore
20All the interconnected feeding relationships in an ecosystem make up a food interaction.chain.network.web.
21The total amount of living tissue within a given trophic level is called the organic mass.trophic mass.energy mass.biomass.
22What is an ecological model of the relationships that form a network of complex interactions among organisms in a community from producers to decomposers?food weban ecosystemfood chaina population
23What animals eat both producers and consumers? herbivoresomnivoreschemotrophsautotrophs
24What is the term for each step in the transfer of energy and matter within a food web? energy pathfood chaintrophic levelfood pyramid
25A bird stalks, kills, and then eats an insect A bird stalks, kills, and then eats an insect. Based on its behavior, which ecological terms describe the bird?herbivore, decomposerproducer, heterotrophcarnivore, consumerautotroph, herbivore
26A snake that eats a frog that has eaten an insect that fed on a plant is a first-level producer.first-level consumer.second-level producer.third-level consumer.
27The trophic levels in the figure illustrate the relative amount of energy at each level.the amount of living organic matter at each level.the relative number of individual organisms at each level.that the producers outnumber first-level consumers.
28In which way does the figure differ from a typical model of trophic levels? Second-level consumers outnumber first-level consumers.Third-level consumers outnumber second-level consumers.First-level consumers outnumber producers.First-level consumers outnumber second-level consumers.
29Only 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 isused in reproduction.stored as body tissue.stored as fat.eliminated as heat.
30Most of the energy available to a consumer trophic level is used by organisms for transfer to the next trophic level.respiration, movement, and reproduction.producing inorganic chemical compounds.performing photosynthesis.
31Which type of pyramid shows the amount of living tissue at each trophic level in an ecosystem? a numbers pyramidan energy pyramida biomass pyramida food pyramid
32Matter can recycle through the biosphere because matter is passed out of the body as waste.matter is assembled into chemical compounds.biological systems do not use up matter, they transform it.biological systems use only carbon, oxygen, hydrogen, and nitrogen.
33The repeated movement of water between Earth’s surface and the atmosphere is called the water cycle.the condensation cycle.precipitation.evaporation.
34Which of the following is NOT recycled in the biosphere? waternitrogencarbonenergy
35What is the process by which bacteria convert nitrogen gas in the air to ammonia? nitrogen fixationexcretiondecompositiondenitrification
36Carbon cycles through the biosphere in all of the following processes EXCEPT photosynthesis.transpiration.burning of fossil fuels.decomposition of plants and animals.
37How is carbon stored in the biosphere? in the atmosphere as carbon dioxideUnderground as fossil fuels and calcium carbonate rockin the oceans as dissolved carbon dioxideall of the above
38Nitrogen fixation is carried out primarily by humans.plants.bacteria.consumers.
39Which of the following has a direct role in the nitrogen cycle? bacterialegumesdecomposersall of the above
40Organisms need nutrients in order to utilize hydrogen and oxygen.carry out essential life functions.recycle chemical compounds.carry out nitrogen fixation.
41The movements of energy and nutrients through living systems are different because energy flows in one direction and nutrients recycle.energy is limited in the biosphere and nutrients are always available.nutrients flow in one direction and energy recycles.energy forms chemical compounds and nutrients are lost as heat.
42Biogeochemical cycling ensures that human activity will have no effect on elements, chemical compounds, and other forms of matter.living organisms will not become limited in any one nutrient.nutrients will be circulated throughout the biosphere.many nutrients will not reach toxic concentrations in the biosphere.
43What can happen after a lake receives a large input of a limiting nutrient? An algal bloom occurs.Algae begin to die and decomposers take over.Nitrogen compounds are recycled.The concentration of oxygen drops below the necessary level.
44The rate at which organic matter is created by producers in an ecosystem is called a limiting nutrient.fertilization.an algal bloom.primary productivity.
45Which is most likely to be a limiting nutrient in a freshwater pond? phosphorusnitrogencarbonpotassium
46If a nutrient is in such short supply in an ecosystem that it affects an animal’s growth, the animal becomes a decomposer.substance is a limiting nutrient.nutrient leaves the food chain.ecosystem will not survive.
47An ecologist who is studying the relationships among the dominant communities in a geographical region is studying an ecosystem.TrueFalse
48A biome is a group of ecosystems that have the same climate and similar dominant communities. TrueFalse
49Ecologists use tools such as binoculars and microscopes to model changes in the environment. TrueFalse
50Ecologists can make predictions using ecological models. TrueFalse
51Producers release carbon dioxide into the atmosphere during the process of photosynthesis. TrueFalse
52Some autotrophs obtain their energy from hydrogen sulfide to produce carbohydrates. TrueFalse
53Animals that feed on plants are called producers. TrueFalse
54The passage of energy from one organism to another according to a particular feeding sequence is called a food chain.TrueFalse
55In an ecological pyramid, the biomass of organisms increases at each successive level. TrueFalse
56Only about 10 percent of the energy in a trophic level is available to organisms at the next trophic level.TrueFalse
57Only about 15 calories are available to a chicken from 1500 calories of grain. TrueFalse
58Scientists classify the nitrogen, carbon, and water cycles as biogeochemical cycles. TrueFalse
59The biosphere actively cycles less than 1 percent of all the carbon on Earth, even though carbon is the key ingredient in all living systems.TrueFalse
60Aquatic ecosystems can receive a large input of a limiting nutrient from the runoff from heavily fertilized fields.TrueFalse
61A lake that is protected from receiving the runoff from a cultivated field is likely to remain a healthy ecosystem.TrueFalse