Question 1

In an ecosystem, phytoplankton are _____.

Accepted Answer

producers

Question 2

An earthworm that feeds on the remains of plants and animals is acting as a _____.

Accepted Answer

detritivore

Question 3

When a human eats a steak, the human is acting as a _____.

Accepted Answer

secondary consumer

Question 4

A cow eating grass is an example of a _____.

Accepted Answer

primary consumer

Question 5

A human who just ate a hamburger is eaten by a shark while swimming. The shark is acting as a _____.

Accepted Answer

tertiary consumer

Question 6

A human eats a deer. Which of these terms applies to the relationship between the human and the deer?

Accepted Answer

predation

Question 7

Humans and sharks both eat fish. Which of these terms applies to the relationship between the human and the shark?

Accepted Answer

competition

Question 8

Humans who have pets tend to be healthier than humans who do not have pets. Which of these terms applies to the relationship between a human and a pet?

Accepted Answer

mutualism: both members of the species pair benefit; in this case the human is healthier and the pet is getting room and board.

Question 9

Which of these terms applies to the relationship between a dog and a blood-sucking tick?

Accepted Answer

parasitism: The tick benefits at the expense of the dog; the dog is the host and the tick is the parasite.

Question 10

Which of these provides your body with energy?

Accepted Answer

fats

Question 11

Plants use _____ as a source of energy.

Accepted Answer

light

Question 12

What element is found in all organic compounds?

Accepted Answer

carbon

Question 13

Where do plants get the carbon they use to make organic molecules?

Accepted Answer

CO2

Question 14

What is the name of the process by which organisms convert the carbon in organic compounds into carbon in carbon dioxide?

Accepted Answer

cellar respiration

Question 15

Which of these is NOT an organic molecule?

Accepted Answer

minerals

Question 16

_____ are secondary consumers.

Accepted Answer

carnivores

Question 17

Approximately _____% of the energy at one trophic level is passed on to the next highest trophic level.

Accepted Answer

5-10%

Question 18

10,000 kcal of producer could support approximately _____ kcal of tertiary consumer.

Accepted Answer

10

Question 19

What name is given to the process by which detritivores return carbon to the atmosphere?

Accepted Answer

Decomposition: the conversion of organic molecules into inorganic molecules, results in the release of carbon dioxide into the atmosphere.

Question 20

Which of these removes carbon from the atmosphere?

Accepted Answer

algae

Question 21

Detritus is composed of _____.

Accepted Answer

dead organic matter and excreted wastes

Question 22

Nitrifying bacteria convert _____ to _____.

Accepted Answer

ammonium ... nitrites

Question 23

_____ removes nitrogen from the atmosphere.

Accepted Answer

nitrogen fixation

Question 24

Assimilation is indicated by the letter(s) _____.

Accepted Answer

A: Assimilation is the uptake of nutrients into an organism.

Question 25

Nitrogen-fixing bacteria is(are) indicated by the letter(s) _____.

Accepted Answer

D and E: Both of these pointers are indicating nitrogen-fixing bacteria. Nitrogen fixation is the conversion of nitrogen to a form that plants can use.

Question 26

Nitrification is indicated by the letter(s) _____.

Accepted Answer

B: Nitrification is the conversion of organic nitrogen-containing compounds to nitrites and nitrates.

Question 27

Denitrifying bacteria convert _____ to _____.

Accepted Answer

nitrates to nitrogen gas

Question 28

Which one of these is a nitrate?

Accepted Answer

NO3-

Question 29

Which one of these is a nitrite?

Accepted Answer

NO2-

Question 30

Which of these are the two major sources of nitrate pollution in rivers?

Accepted Answer

animal waste and fertilizers

Question 31

Aquatic nitrate pollution can result in _____.

Accepted Answer

an algal bloom that, when the algae die and are decomposed by bacteria, leads to hypoxia and the death of fish

Question 32

All the organisms in a particular area make up a(n) __________

Accepted Answer

community

Question 33

According to the principle of interspecific competition, two species cannot continue to occupy the same __________.

Accepted Answer

ecological niche

Question 34

In terms of + (this member of a species pair benefits from the interaction), - (this member of a species pair is harmed by the interaction), and 0 (this member of a species pair is unaffected by the interaction), predation can be described as a __________ relationship.

Accepted Answer

+/-

Question 35

An organism's trophic level refers to _________

Accepted Answer

what it eats

Question 36

Consider the following segment of a food web: Snails and grasshoppers eat pepper plants; spiders eat grasshoppers; shrews eat snails and spiders; and owls eat shrews. The shrew occupies the trophic level(s) of __________.

Accepted Answer

secondary and tertiary consumers

Question 37

Why do toxins accumulate at such high levels in carnivores?

Accepted Answer

The biomass at any given trophic level is accumulated from a much larger toxin-containing biomass ingested from the level below.: Remember that only 10% of the energy is transferred from one level to the next. Thus, a top carnivore quickly accumulates the largest amounts of toxin.

Question 38

Which of the following describes the number of different species in the community?

Accepted Answer

species richness

Question 39

Which of the following is an example of primary succession?

Accepted Answer

the colonization of a newly formed volcanic island: This is the succession from a barren, lifeless area to a community of organisms.

Question 40

The energy for nearly every organism in almost every ecosystem ultimately comes from _____.

Accepted Answer

the sun

Question 41

The energy flow through the trophic levels of an ecosystem is represented as a pyramid because __________.

Accepted Answer

only about 10% of the energy at each trophic level is available at the next level

Question 42

Biogeochemical cycles are crucial to ecosystem function because __________.

Accepted Answer

nutrients and other life-sustaining molecules are in limited supply and must be continually recycled

Question 43

An ecosystem is unlikely to be limited by the supply of _____ because it is obtained from the air.

Accepted Answer

carbon

Question 44

Which of the following impacts the nitrogen cycle?

Accepted Answer

the use of large amounts of inorganic fertilizers

Question 45

The study and protection of biological diversity is a field called __________.

Accepted Answer

conservation biology

Question 46

Biodiversity hot spots are __________.

Accepted Answer

regions with the potential for high levels of extinction

Question 47

Edge species __________.

Accepted Answer

may require conditions found in both of the bordering ecosystems: The cowbird is an edge species that feeds in open fields and parasitizes the nests of other bird species in the forest.

Question 48

The use of living organisms to detoxify polluted ecosystems is called _____.

Accepted Answer

bioremediation: Restoration projects have the broad goal of returning ecosystems to their natural state.

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