Deck 29: Energy Flow and Nutrient Cycling in Ecosystems

Question 1

If the plants in a community produce 500 grams of organic matter per square meter per year that is available for animals in the community to eat, this amount of energy is known as the

A) secondary productivity of the community.
B) trophic factor of the community.
C) net primary productivity of the community.
D) consumership of the community.
E) availability factor of the community.

Answer 1

C

Question 2

If a fox eats a rodent that ate a smaller insect that ate a plant, the fox is a(n)

A) autotroph.
B) tertiary consumer.
C) primary consumer.
D) producer.
E) secondary consumer.

Answer 2

B

Question 3

The photosynthetic bacteria that form the basis of the food chain in the Great Salt Lake are classified as

A) omnivores.
B) carnivores.
C) secondary consumers.
D) herbivores.
E) producers.

Answer 3

E

Question 4

If a bird eats an insect that ate a plant, the bird is considered a(n)

A) producer.
B) tertiary consumer.
C) autotroph.
D) primary consumer.
E) secondary consumer.

Question 5

The atoms that make up the molecules in our bodies

A) have nearly all been on Earth throughout its entire history.
B) were all formed recently by nuclear fusion on the sun.
C) were once part of a dinosaur.
D) will be lost back to space soon after we die.
E) came from a wooly mammoth.

Question 6

Which level of the energy pyramid has the greatest biomass?

A) Secondary consumers
B) Primary consumers
C) Heterotrophs
D) Carnivores
E) Producers

Question 7

The amount of energy captured by plants and made available to consumers in an ecosystem is called

A) biological magnification.
B) nutrient cycling.
C) net primary productivity.
D) energy pyramid.
E) secondary trophic level.

Question 8

The first trophic level of an ecosystem consists of

A) secondary consumers.
B) primary consumers.
C) producers.
D) detritus feeders.
E) heterotrophs.

Question 9

What are the most basic components of all ecosystems?

A) Nutrients and energy
B) Communities of organisms
C) The living, or biotic part, and the abiotic
D) Producers, consumers, and decomposers
E) Volcanoes, wind, oceans, and other abiotic parts

Question 10

A carnivore is usually a(n)

A) secondary producer.
B) primary consumer.
C) secondary consumer.
D) primary producer.
E) autotroph.

Question 11

A carnivorous plant, such as a sundew, may be considered both a __________when it eats a carnivorous spider.

A) producer and a tertiary consumer
B) primary consumer and a tertiary consumer
C) producer and a secondary consumer
D) producer and a primary consumer
E) primary consumer and a secondary consumer

Question 12

The__________ are an important and often overlooked group of organisms that release nutrients into the soil or water.

A) producers
B) tertiary consumers
C) autotrophs
D) heterotrophs
E) decomposers

Question 13

How much of the energy that reaches Earthʹs outer atmosphere from the sun is available for photosynthesis in plants at Earthʹs surface?

A) 95%
B) 1%
C) 55%
D) 71%
E) 44%

Question 14

A deer that gets its energy from eating plants is a(n)

A) producer.
B) tertiary consumer.
C) herbivore.
D) carnivore.
E) omnivore.

Question 15

The amount of energy lost as it passes from one trophic level to another is approximately

A) 99%.
B) 50%.
C) 63%.
D) 75%.
E) 90%.

Question 16

What proportion of the solar radiation that reaches Earthʹs surface is visible light?

A) About 90% of it is visible light.
B) A small fraction is visible light.
C) It is captured by plants and used in photosynthesis.
D) Most of the radiation is absorbed by rocks on Earthʹs crust.
E) About half is visible light.

Question 17

Organisms that must rely on complex, high-energy molecules produced by other organisms for survival are

A) producers.
B) heterotrophs.
C) autotrophs.
D) cyanobacteria.
E) denitrifying bacteria.

Question 18

The amount of life that an ecosystem can support is determined primarily by the

A) efficiency of the consumers.
B) number of producers and their efficiency.
C) efficiency of the heterotrophs.
D) number of heterotrophs.
E) number of chemoautotrophs.

Question 19

Certain bacteria and fungi that are important in nutrient recycling because they release nutrients from dead organisms back into the ecosystem are

A) carnivores.
B) recyclers.
C) detritus feeders.
D) autotrophs.
E) decomposers.

Question 20

If a field contains approximately 1,000 kilocalories of energy in grass, which is eaten by crickets, which are eaten by birds, then approximately how many kilocalories of energy could be in the birds that live in this field?

A) 1,000
B) 10
C) 100
D) 900
E) 90

Question 21

Net primary production is

A) heterotrophic production per unit of land per unit of time.
B) energy that photosynthetic organisms make available to other organisms over a given period of time.
C) heterotrophic production minus autotrophic production per unit of land per unit of time.
D) energy made by autotrophs minus energy consumed by heterotrophs, and measured as biomass.
E) energy stored by secondary consumers from primary biomass.

Question 22

Oceans, the atmosphere, and fossil fuels are large reservoirs of

A) phosphorus.
B) water.
C) nitrogen.
D) oxygen.
E) carbon.

Question 23

In a grassland of Kansas, 1,000 grams of grass are produced per square meter per year by all the different grass species. A theoretical upper limit to the biomass of secondary consumers that can be supported in this ecosystem is

A) 10 grams.
B) 0.1 gram.
C) 1,000 grams.
D) 100 grams.
E) 1 gram.

Question 24

In 1956, people in Minamata, Japan, began to exhibit severe neurological disorders and birth defects. This problem was eventually attributed to methylmercury, a water-insoluble and breakdown-resistant chemical formed from mercury dumped into the adjacent bay by a local factory. Which of the following types of seafood would have the highest levels of methylmercury, and therefore cause the severest effects?

A) Kelp (large, multicellular, photosynthetic protists)
B) Krill (small crustaceans that eat tiny microscopic algae)
C) Sea urchins that feed on kelp
D) Mussels that feed on tiny microscopic algae
E) Tuna that feed on smaller fish that feed on krill that feed on algae

Question 25

If you are attempting to minimize the amount of mercury in your diet, you should eat

A) omnivores such as hogs.
B) herbivores such as cattle.
C) producers such as fruits and vegetables.
D) low-level carnivores such as tilapia.
E) high-level carnivores such as tuna.

Question 26

What is biological magnification?

A) The accumulation of toxic substances in a living organism
B) An increase in the size of a population
C) The breakdown of macromolecules into harmless substances
D) The abnormal growth of organisms
E) The process of making small living organisms larger

Question 27

Bacteria that live in deep-sea thermal vents use energy from inorganic hydrogen sulfide (H 2S) to make organic molecules from carbon dioxide and are thus

A) primary consumers.
B) secondary consumers.
C) decomposers.
D) producers.
E) tertiary consumers.

Question 28

Which of the following terms correctly describes carnivores?

A) Autotrophs
B) Detritus consumers
C) Secondary consumers
D) Primary consumers
E) Consumer producers

Question 29

Phosphorus, which is often a limiting nutrient in ecosystems, is important because it

A) evaporates quickly.
B) is found only in sedimentary rocks.
C) is necessary for the production of cellulose so that autotrophs can grow and provide food for heterotrophs.
D) is part of the hydrologic cycle.
E) is needed for molecules such as adenosine triphosphate (ATP), cell membranes, and nucleic acids.

Question 30

The three major reservoirs of carbon are

A) acid precipitation, carbon-fixing bacteria, and oceans.
B) soil, water, and the atmosphere.
C) rocks, the atmosphere, and guano.
D) oceans, the atmosphere, and fossil fuels.
E) fossil fuels, legumes, and micronutrients.

Question 31

A snake that eats a small rabbit that feeds on grass is classified as a(n)

A) primary consumer.
B) secondary consumer.
C) tertiary consumer.
D) autotroph.
E) primary producer.

Question 32

Autotrophs gain energy from

A) omnivores.
B) secondary producers.
C) secondary consumers.
D) primary producers.
E) the sun and inorganic nutrients.

Question 33

__________is (are) a crucial nutrient reservoir of phosphorus that is available to organisms.

A) Consumers
B) Oceans
C) Rocks
D) Autotrophs
E) The atmosphere

Question 34

Which nutrient cycle lacks an atmospheric reservoir?

A) Nitrogen
B) Oxygen
C) Carbon
D) Phosphorus
E) Water

Question 35

Which of the following components is NOT involved in the phosphorus cycle?

A) The atmosphere
B) Producers
C) Consumers
D) Decomposers
E) Some rocks and soil

Question 36

Which trophic level has the LEAST biological magnification?

A) Tertiary consumers
B) Heterotrophs
C) Secondary consumers
D) Primary consumers
E) Primary producers

Question 37

The community of detritivores, such as earthworms, millipedes, slugs, and pseudoscorpions, living in the leaf litter on the shady floor of a deciduous forest obtains its energy and nutrients primarily from

A) decomposition of the leaves of deciduous trees that fall on the surface of the soil.
B) photosynthesis or algae living in the soil beneath the leaves.
C) carbohydrates formed in the roots of the trees that leach out into the surrounding soil.
D) predation on one another.
E) chemosynthesis by green and purple sulfur bacteria living on the surface of the leaves.

Question 38

In open-water marine ecosystems, the__________ occupy the same trophic level as the giant sequoias (redwoods) in the forests of California.

A) tiny, multicellular zooplankton (?animal drifters?) that feed on phytoplankton
B) fast-swimming, fish-eating tuna
C) microscopic, single-celled algae (protists) called phytoplankton (?plant-like drifters?)
D) giant, squid-eating whales
E) microscopic bacteria that decompose all the other organisms once they have died

Question 39

If a couple was attempting to get pregnant, which foods should they eat to avoid ingesting high amounts of toxins?

A) High-fat salmon
B) High-level carnivores such as tuna
C) Organic grains, fruits, and vegetables
D) Meals microwaved in plastic bags
E) DDT-treated vegetables

Question 40

Detritus feeders consume

A) herbivores.
B) fungi and bacteria.
C) secondary consumers and primary debris.
D) dead organic matter.
E) plants and plant debris.

Question 41

Forests along rivers in the Pacific Northwest that have lost their salmon populations are less productive because the

A) fishers who overharvested the salmon compacted the soil in the process.
B) nitrogen the fish brought from the ocean and contained in their tissues has been lost.
C) pollution that killed the fish has also directly affected the trees.
D) global warming that wiped out the fish has also harmed the trees.
E) dams that prevented the fish from migrating also flooded the forests.

Question 42

Farmers often include legumes as part of their normal crop rotation. This practice increases the overall production of their crops by

A) making the soil less acidic.
B) adding nitrogen to the soil.
C) adding phosphorus to the soil.
D) suppressing the growth of weeds.
E) helping the soil retain water.

Question 43

Why is the concentration of carbon dioxide in Earthʹs atmosphere rapidly increasing?

A) The ozone layer has become much thinner.
B) The oceans are cooling.
C) Earth is warming.
D) Many human activities release carbon dioxide.
E) More photosynthesis is occurring.

Question 44

In an area with nitrogen-poor soil, legumes often dominate over other plants because they

A) have unique access to the large atmospheric pool of nitrogen thanks to their symbiotic bacteria.
B) do not need nitrogen at all.
C) have long taproots that can extract nitrogen from deeper down in the soil.
D) obtain supplemental nitrogen by trapping insects and other prey.
E) inhibit the growth of denitrifying bacteria around their roots, thus keeping more nitrate in the soil.

Question 45

Once used by an organism, carbon- and nitrogen-based nutrients are unavailable for other organisms.

Question 46

The greenhouse effect is the ability of

A) sulfur dioxide and nitrogen oxides to retain heat in the upper atmosphere.
B) sulfur dioxide and nitrogen oxides to retain heat in the lower atmosphere.
C) certain gases to absorb solar heat and reflect the heat to Earth as short-wave radiation.
D) structures created by humans to retain solar energy as short-wave radiation.
E) certain gases to retain heat in the atmosphere instead of allowing it to be reflected back into space.

Question 47

Micronutrients

A) include water, carbon, nitrogen, and phosphorus.
B) benefit organisms if they are present but are not essential.
C) are needed in smaller quantities than are macronutrients.
D) are not naturally occurring and must be synthesized by scientists.
E) are smaller molecules than are macronutrients.

Question 48

Acid deposition is the result of interference with the __________cycles.

A) sulfur and nitrogen
B) sulfur and hydrologic
C) hydrologic and phosphorus
D) hydrologic and nitrogen
E) sulfur and phosphorus

Question 49

Nitrogen is the most abundant element in the atmosphere, and a crucial component of proteins, vitamins, and nucleic acids. However, plants and other producers cannot use nitrogen in its natural form (N₂). Nitrogen has to undergo a process called nitrogen fixation. What does this process involve?

A) It is undertaken by denitrifying bacteria.
B) Nitrogen is accumulated in dead organic matter.
C) Ammonia is converted to nitrate.
D) Nitrate is converted to ammonia.
E) It is the synthesis of ammonia from nitrogen gas by certain bacteria.

Question 50

Each summer, a large ʺdead zoneʺ devoid of fish and other animals develops where the Mississippi River flows into the Gulf of Mexico. What causes this?

A) Large quantities of fertilizer run off from Midwestern farm fields into the Mississippi River.
B) Acid rain makes the gulfʹs water too acidic to support fish.
C) High levels of pesticides are used in the Mississippi River basin.
D) There are high levels of mercury in the river water.
E) Global warming is making the river water too hot for the fish to tolerate.

Question 51

Human-caused disturbances of the__________ cycle may be contributing to global warming.

A) carbon
B) hydrologic
C) sulfur
D) phosphorus
E) oxygen

Question 52

When nitrogen oxides and sulfur dioxide combine with water vapor in the air, they are converted to nitric acid and sulfuric acid, respectively. This precipitation that then falls to the Earth is known as

A) acid deposition.
B) acid fog.
C) acid precipitation.
D) decomposition acid.
E) nitrogen precipitation.

Question 53

Burning coal and oil to release energy also releases__________ , which are overloading Earth?s nutrient cycles.

A) phosphorus, carbon, and nitrogen
B) oxygen, methane, and sulfur
C) sulfur, carbon, and nitrogen
D) sulfur, oxygen, and acid
E) nitrogen, phosphorus, and potassium

Question 54

The hydrologic cycle is different from other nutrient cycles in that

A) the soil is not involved.
B) water is not recycled, but flows one way through ecosystems.
C) the biotic part of the cycle plays only a small role.
D) the ocean is involved.
E) the atmosphere is involved.

Question 55

The present range of the sugar maple in North America extends from the Atlantic Ocean west to the Mississippi River and from southern Ontario, Quebec, and New Brunswick south to Tennessee and Virginia. If the global temperature rises 10°C in the future, where will the range of sugar maples be found?

A) Farther south
B) Farther west
C) Farther north
D) In the same place; global warming will not affect the heat tolerance of plants.
E) Nowhere; sugar maples will become extinct.

Question 56

Carbon dioxide and other greenhouse gases cause Earthʹs temperature to increase by

A) increasing plant respiration.
B) increasing the amount of radiation from Earthʹs surface.
C) allowing greater transmission of incoming solar radiation.
D) reducing photosynthetic rates.
E) absorbing heat energy and holding it close to Earth.

Question 57

What are the sources of sulfur in the atmosphere?

A) Decomposition and small amounts from pollution
B) Mostly transportation modes, such as autos, trucks, and planes
C) Volcanoes and hot springs, but mostly (about 75%) human activities such as burning coal
D) Natural and human sources, in equal amounts
E) Mostly (over 90%) volcanoes and photosynthetic bacteria

Question 58

When you observe a lake that has been affected by acid deposition, you might expect to find

A) a murky lake with excess algal growth from the deposition of anthropogenic nitrogen.
B) high levels of dissolved sulfur dioxide.
C) low levels of toxic metals and nutrients essential for the growth of biotic organisms.
D) a clear lake with high levels of aluminum, mercury, and lead, but few fish.
E) excess carbon that will contribute to global warming.

Question 59

Phosphate fertilizers have increased the amount of phosphate in lakes and other bodies of water. What effect does this increase have on the phytoplankton in the water?

A) It causes them to form toxic compounds.
B) It increases their likelihood of being eaten.
C) It stimulates their growth.
D) It kills them.
E) It reduces their photosynthetic capacity.

Question 60

The greenhouse effect, which has become a major ecological concern, is caused by

A) the release of heat energy from burning fossil fuels.
B) overuse of fertilizers in farming.
C) global warming.
D) the destruction of ozone in the upper atmosphere.
E) the increase in atmospheric concentrations of greenhouse gases (CO2,CH4, and N2O).

Question 61

Horses and cows are primary consumers.

Question 62

Organisms that produce their own food from inorganic compounds through reactions powered by sunlight are heterotrophs.

Question 63

Carbon dioxide is the only greenhouse gas.

Question 64

Macronutrients are elements or small molecules that are needed in only trace amounts.

Question 65

Burning high-sulfur coal increases acid deposition.

Question 66

Plants absorb small amounts of carbon from the soil in the form of simple sugars or monosaccharides.

Question 67

When a rabbit eats the lettuce in your garden, the rabbit uses all of the energy in the lettuce.

Question 68

Autotrophs use solar energy to build their own complex organic molecules from inorganic compounds such as water and carbon dioxide.

Question 69

One of the basic principles of ecosystems is that __________moves through the ecosystems in a continuous one-way flow.

Question 70

The primary consumers in marine food chains are phytoplankton.

Question 71

Detritus feeders remove nutrients from the food chain.

Question 72

Iron is a limiting factor in many aquatic ecosystems. If the iron level is increased, the amount of phytoplankton (which feed on iron) decreases.

Question 73

The major reservoir in the nitrogen cycle is the water.

Question 74

The primary source of Earthʹs energy is the sun.

Question 75

Aquifers are underground reservoirs in the hydrologic cycle.

Question 76

The level of environmental toxins such as DDT decreases as you move into the higher trophic levels.

Question 77

Many climatologists blame the recent extremes in weather on global warning.

Question 78

Deforestation decreases the levels of greenhouse gases in the atmosphere.

Question 79

Plants often grow poorly in sterilized soils because the soils lack nitrogen-fixing bacteria.

Question 80

Fossil fuels are the major reservoir in the phosphorus cycle.