Deck 15: Ecosystem Dynamics: The Flow of Energy and Matter

Question 1

In the phosphorus cycle the ultimate source of phosphorus is

A) rock.
B) dead organisms.
C) plants.
D) the sun.

Answer 1

rock.

Question 2

In the carbon cycle the two primary processes that remove and add carbon dioxide to the atmosphere are

A) predation and parasitism.
B) carnivores and herbivores.
C) sunlight and photosynthesis.
D) respiration and photosynthesis.

Answer 2

respiration and photosynthesis.

Question 3

As with all organic molecules, carbon forms the backbone of the molecules that comprise plant tissue. This carbon comes from

A) the soil, and was taken up through the plant's roots.
B) the organic molecules produced by aerobic cellular respiration.
C) the atmosphere as CO₂.
D) the splitting of water molecules.

Answer 3

the atmosphere as CO₂.

Question 4

The role of decomposers is important to all of the following cycles except the

A) carbon cycle.
B) hydrologic cycle.
C) nitrogen cycle.
D) phosphorus cycle.

Question 5

Most of the processes that influence the hydrologic cycle are

A) biological processes.
B) physical processes.
C) ecosystem processes.
D) wind processes.

Question 6

The hydrologic cycle involves

A) the formation of water molecules from hydrogen and oxygen in the atmosphere.
B) the manufacture of water during photosynthesis in plants.
C) the consumption of water during aerobic cellular respiration.
D) None of these answers is correct.

Question 7

A demonstration of the second law of thermodynamics is

A) the amount of energy coming from the sun.
B) that carnivores require more energy than herbivores.
C) that there is more producer biomass than herbivore biomass in an ecosystem.
D) the high proportion of protein in the diets of Americans.

Question 8

The difference between an ecosystem and a community is that the ecosystem has something a community does not have; the ecosystem has

A) producers.
B) consumers.
C) nonliving parts.
D) interacting species.

Question 9

The amount of plant biomass in an area may increase if there is an increase in the amount of

A) symbiotic nitrogen-fixing bacteria.
B) succession.
C) competition.
D) denitrifying bacteria.

Question 10

Decomposers

A) are unimportant links in a food web.
B) recycle organic to inorganic compounds.
C) cause disease and destruction.
D) require a source of light energy.

Question 11

A food chain always begins with

A) sympathetic decomposers.
B) photosynthetic autotrophs.
C) pathetic instructors.
D) heterotrophic consumers.

Question 12

A food web is

A) a long food chain.
B) several food chains that intersect.
C) a trap to catch food.
D) a complicated series of passages of energy via the first law of thermodynamics.

Question 13

If it were part of a food web, a pigeon could be eaten by

A) humans.
B) hawks.
C) cats and dogs.
D) All of these answers are true.

Question 14

The environment of an organism would include its

A) enemies.
B) food.
C) diseases.
D) All of these answers are true.

Question 15

Which of the following is NOT recycled?

A) nitrogen
B) water
C) energy
D) carbon

Question 16

Which of the following is true of nitrogen?

A) N₂ is scarce in the atmosphere, therefore, plants must obtain other sources of nitrogen.
B) Animals require nitrogen from the food they eat for the synthesis of carbohydrates and lipids.
C) Nitrogen-fixing bacteria convert N₂ into compounds plants can utilize.
D) Nitrogen is plant food and, therefore, provides plants with energy.

Question 17

Which of the following can serve as a direct source of nitrogen for plants?

A) nitrogen gas in the air
B) amino acids in dead organisms
C) ammonia from the decomposition of dead organisms
D) denitrifying bacteria in the soil

Question 18

Pests that eat the same type of food as humans are part of our

A) producers.
B) food web.
C) food chain.
D) All of these answers are true.

Question 19

All food chains begin with a

A) herbivore.
B) carnivore.
C) producer.
D) decomposer.

Question 20

The amount of rain an area gets is part of an organism's

A) biotic factors.
B) abiotic factors.
C) community.
D) succession.

Question 21

Since snakes, people, and fish all like to eat frogs, this is an example of a

A) food web.
B) food chain.
C) preference test.
D) trophic level variation.

Question 22

Which is a food chain?

A) grass-grasshopper-horse
B) fish-grasshopper-snake
C) light-grass-human
D) grass-cow-human

Question 23

Nitrites (--NO₂) are converted to nitrogen gas (N₂) by

A) decomposers.
B) nitrogen-fixing bacteria.
C) nitrifying bacteria.
D) denitrifying bacteria.

Question 24

Which of the following would be at the highest trophic level?

A) a lion
B) a grasshopper
C) a mushroom
D) a grass plant

Question 25

Which of the following is likely to have the highest biomass in an ecosystem?

A) grasshopper
B) frog
C) cow
D) grass

Question 26

Which of the following is likely to have the lowest numbers in an ecosystem?

A) producers
B) carnivores
C) herbivores
D) consumers

Question 27

As energy passes through a food chain, approximately ____ percent is lost as it passes through each trophic level.

A) 10
B) 25
C) 50
D) 90

Question 28

Which of the following is part of the abiotic environment of an organism?

A) grass
B) rain
C) food
D) decomposers

Question 29

____ convert nitrogen gas to nitrogen that plants can use.

A) Decomposers
B) Nitrogen-fixing bacteria
C) Nitrifying bacteria
D) Denitrifying bacteria

Question 30

If the world were to support the largest possible human population, all humans would need to be

A) carnivores.
B) omnivores.
C) herbivores.
D) producers.

Question 31

The nutrient that is in short supply for many people of the world is

A) protein.
B) calories.
C) fat.
D) water.

Question 32

Phosphorus is needed by organisms for

A) DNA.
B) bones.
C) cell membranes.
D) All of these answers are correct.

Question 33

The branch of science that deals with the study of organisms and how they interact with their environment is known as

A) biology.
B) the biome.
C) ecology.
D) abiotic.

Question 34

Which of the following would be a consumer?

A) a cow
B) a tree
C) wind
D) grass

Question 35

Ammonia (NH₃) is converted to nitrite (--NO₂) by

A) decomposers.
B) nitrogen-fixing bacteria.
C) nitrifying bacteria.
D) denitrifying bacteria.

Question 36

The nitrogen in your body came from the

A) proteins in the food you eat.
B) carbohydrates in the food you eat.
C) air you breathe.
D) water you drink.

Question 37

Human use of ecosystems

A) is in harmony with natural ecosystems.
B) increases the number of animals present.
C) requires the alteration of previously existing ecosystems.
D) does not occur.

Question 38

Which of the following would be a primary consumer?

A) tree
B) decomposer
C) carnivore
D) herbivore

Question 39

-In the diagram above, the most biomass is contained within the

A) trees.
B) insects.
C) frogs.
D) human.

Question 40

The insects in the diagram above represent all of the following except

A) herbivores.
B) the second trophic level.
C) primary consumers.
D) producers.

Question 41

As represented in the diagram above, which of the following organisms are carnivores?

A) human and fish only
B) human, fish, and frog only
C) human, fish, frog, and spider only
D) human, fish, frog, spider, and insect only

Question 42

The ____ in the diagram above is a tertiary consumer.

A) spider
B) frog
C) fish
D) human

Question 43

The most energy is contained within the ____ in the figure diagram above.

A) human
B) frogs
C) trees
D) Each level contains identical amounts of energy. (Energy cannot be created or destroyed.)

Question 44

____ in the figure diagram above represent consumers.

A) Only the plants
B) Only the insects
C) Everything except trees
D) Spiders, frogs, fish, and humans

Question 45

The spiders in the diagram above are

A) tertiary consumers.
B) herbivores.
C) at the third trophic level.
D) omnivores.

Question 46

If 100,000 units of energy are contained within the trees in the diagram above, ____ units of energy are stored within the ___.

A) 1,000; spiders
B) 10; humans
C) 100; fish
D) 1,000; frogs

Question 47

The following sequence of organisms represents all of the following except trees $\rightarrow$ insects $\rightarrow$ spiders $\rightarrow$ frogs $\rightarrow$ fish $\rightarrow$ human

A) a food chain.
B) a food web.
C) the flow of energy through the community.
D) the flow of nutrients through the community.

Question 48

The following sequence of organisms is not an accurate representation of a community in that frogs could actually feed upon insects or spiders, fish could feed on either frogs or insects, and humans enjoy fish, frogs, tree products, and, in some cases, even insects. A more complete representation of these interactions would be a(n) trees $\rightarrow$ insects $\rightarrow$ spiders $\rightarrow$ frogs $\rightarrow$ fish $\rightarrow$ human

A) energy pyramid.
B) food chain.
C) biome schematic.
D) food web.

Question 49

An animal that eats both plants and animals is

A) a herbivore.
B) an omnivore.
C) a carnivore.
D) decomposer.

Question 50

Producers are involved in which of the following processes?

A) photosynthesis only
B) respiration only
C) both photosynthesis and respiration
D) None of the above is correct.

Question 51

Each trophic level represents approximately a _____ percent energy ____.

A) 10; loss
B) 90; transfer
C) 50: loss
D) 90; loss

Question 52

A collection of interacting organisms of different species is a(n)

A) ecosystem.
B) community.
C) population.
D) habitat.

Question 53

All of the ____ are a community.

A) sugar maple trees on Earth
B) living organisms in a forest
C) squirrels in a forest
D) living and nonliving things in the forest

Question 54

____ is a biotic factor in an ecosystem.

A) Water
B) Light
C) Soil
D) A bacterium

Question 55

Climate change (global warming) is directly related to

A) the amount of carbon dioxide in the atmosphere.
B) humans eating protein.
C) the loss of carbon dioxide from the oceans.
D) the size of the human population.

Question 56

Which one of the following is NOT true of biomass?

A) Biomass is greatest in producers.
B) Biomass is a measure of productivity.
C) Biomass is the dry weight of organisms.
D) Biomass shows a loss of 10% at each trophic level.

Question 57

If decomposers ceased to exist, you would expect

A) photosynthesis to stop.
B) organic matter to build up.
C) few changes.
D) increased numbers of herbivores.

Question 58

Energy is lost as one proceeds from the producer to herbivore trophic level because:

A) herbivores must expend energy to chew and process food.
B) of the second law of thermodynamics.
C) herbivores lose heat to their surroundings.
D) All of the above are correct.

Question 59

In the food chain grass ? mice ? coyotes:

A) the total biomass of all the coyotes is greater than the total biomass of all the mice.
B) the mice are the producers.
C) the total amount of energy contained within the bodies of all the mice in the area is much greater than the total energy in the bodies of all the coyotes.
D) coyotes eat primarily grass.

Question 60

A pyramid of numbers gives a reasonably accurate representation of the relationship between trophic levels when

A) all the organisms are consumers.
B) all the organisms are about the same size.
C) all the organisms are the same age.
D) all the animals are carnivores.

Question 61

The source of energy for nearly all ecosystems is

A) the sun.
B) food.
C) oxygen.
D) water.

Question 62

Ponds have pondweeds attached to the bottom, insect larvae that feed on the pondweeds, fish that eat the insects, and birds like great blue herons that eat the fish. In this ecosystem which of the following would have the largest total biomass (all individuals of the category)?

A) large fish
B) small fish
C) insects
D) great blue herons

Question 63

People who live in poor countries have diets that are made up primarily of plant materials. This is because

A) plant foods are less expensive than are animal foods.
B) many calories would be lost if they fed plants to animals.
C) more people can be supported at the herbivore level than at the carnivore level.
D) All of these answers are true.

Question 64

The atmosphere contains approximately ____ percent nitrogen.

A) 2
B) 10
C) 50
D) 80

Question 65

In general, there is about a ______ percent loss of energy as we proceed from one trophic level to the next higher level.

A) 90
B) 80
C) 60
D) 50

Question 66

Which of the following is the BEST example of a primary carnivore?

A) lion
B) corn plant
C) shark
D) goat

Question 67

Plants get the nitrogen they need to build additional cells from

A) protein in the cells.
B) ammonia or nitrate in the soil.
C) denitrifying bacteria.
D) directly from the nitrogen in air.

Question 68

Grass, mice, snakes, and hawks living together in the same geographic area constitute a/an

A) ecosystem.
B) abiotic factor.
C) community.
D) environment.

Question 69

Marine algae would be considered a part of which trophic level?

A) producer
B) primary consumer
C) secondary consumer
D) tertiary consumer

Question 70

Carbon first becomes part of a living thing as a result of

A) nitrogen-fixing bacteria.
B) decomposer organisms.
C) photosynthesis.
D) aerobic respiration.

Question 71

The nitrogen found in carnivores would follow which of the following paths?

A) plant $\rightarrow$ air $\rightarrow$ carnivore
B) herbivore $\rightarrow$ plant $\rightarrow$ air $\rightarrow$ carnivore
C) air $\rightarrow$ bacteria $\rightarrow$ plant $\rightarrow$ herbivore $\rightarrow$ carnivore
D) air $\rightarrow$ plant $\rightarrow$ bacteria $\rightarrow$ herbivore $\rightarrow$ carnivore

Question 72

The carbon found in carnivores would follow which of the following paths?

A) plant $\rightarrow$ air $\rightarrow$ carnivore
B) herbivore $\rightarrow$ plant $\rightarrow$ air $\rightarrow$ carnivore
C) air $\rightarrow$ bacteria $\rightarrow$ plant $\rightarrow$ herbivore $\rightarrow$ carnivore
D) air $\rightarrow$ plant $\rightarrow$ herbivore $\rightarrow$ carnivore

Question 73

In places where large numbers of seabirds or bats congregate for hundreds of years, the thick deposits of their droppings (called guano) can be a significant source of

A) helium.
B) cyanide.
C) carbon.
D) phosphorus.

Question 74

The loss of water from the surface of plants is

A) transpiration.
B) dew.
C) biomagnification.
D) bioaccumulation.

Question 75

Transpiration is

A) the process by which bacteria converts ammonia into nitrite.
B) a type of symbiotic relationship.
C) the accumulation of a pesticide as it moves through a food chain.
D) the loss of water from plant surfaces.

Question 76

Which of the following nutrient cycles relies heavily on the role of bacteria?

A) carbon cycle
B) hydrologic cycle
C) nitrogen cycle
D) phosphorus cycle

Question 77

This is defined as the rate at which an ecosystem can accumulate new organic matter.

A) productivity
B) assimilation
C) energy cycling
D) thermodynamics