Biology 100 Unit 24

Question 1

– The expanding human population threatens
– ________________________
– ________________________

Answer 1

Biodiversity

The loss of natural resources

Question 2

Healthy ecosystems: (4 things)

Answer 2

– Purify air and water – Decompose wastes – Recycle nutrients
– Pollinate crops

Question 3

An organism’s biotic environment includes

Answer 3

– Other individuals in its own population

– Populations of other species living in the same area

Question 4

– An assemblage of species living close enough together for potential interaction is called a ____________________.

Answer 4

community

Question 5

are interactions between species. Classified according to effect organisms involved

Answer 5

Interspecific interactions

Question 6

_____ interactions occur when two populations in a community compete for a common resource.

Answer 6

-/-

Question 7

_____ interactions are mutually beneficial, such as between plants and their pollinators.

Answer 7

+/+

Question 8

_____ interactions occur when one population benefits and the other is harmed, such as in predation.

Answer 8

+/-

Question 9

In interspecific (between species) competition, the population growth of a species may be limited by
– The population densities of \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ – By the density of its \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 9

competing species (-/-)
own population

Question 10

 An ecological ___________ is the sum of an organism’s abiotic and biotic resources in its environment.

Answer 10

niche

Question 11

Interspecific competition occurs when

Answer 11

the niches of two populations overlap.

Question 12

The _____________________________ states that if two species have an ecological niche that is too similar, the two species cannot coexist in the same place.

Answer 12

competitive exclusion principle

Question 13

These different species of warblers have an ecological niche that overlaps, leading to ___________________

Answer 13

interspecific competition (+/-) they cant live together

Question 14

In mutualism, ___________________________________.  An example of mutualism includes reef-building corals and
photosynthetic dinoflagellates.

Answer 14

both species from an interconnection

Question 15

The photosynthetic dinoflagellates
– gain shelter in the cells of each coral polyp,
– produce sugars used by the polyps, and
– provide at least half of the energy used by the coral animals.
– ___________________________

Answer 15

both organisms benefit

Question 16

Numerous adaptations for predator avoidance have evolved in

Answer 16

prey populations through natural selection.

Question 17

– Cryptic coloration is ___________________ – A way for prey to hide from predators

Answer 17

camouflage

Question 18

– A warning coloration is a ___________________
– Way to warn predators that an animal has an
effective chemical defense

Answer 18

brightly colored pattern

Question 19

– Mimicry is a form of defense in which one _______ ___________________.

Answer 19

animal looks like another species

Question 20

is the consumption of plant parts or algae by an animal.

Answer 20

Herbivory (+/–)

Question 21

Herbivores and plants undergo

Answer 21

coevolution,

Question 22

coevolution:
– a series of reciprocal _____________________
________________________,
– in which change in one species acts as a new selective force on another.

Answer 22

evolutionary adaptations

Question 23

A plant whose body parts have been eaten by an animal must

Answer 23

expend energy to replace the loss.

Thus, numerous defenses against herbivores have evolved in plants.

Question 24

– Plant defenses against herbivores include
– ______________________
– ______________________

Answer 24

• spines and thorines

- chemical toxins

Question 25

Plants and animals can be victims of

Answer 25

parasites and pathogens

Question 26

__________ an organism that lives in or on a _______ | from which it obtains nutrients

Answer 26

parasites, host

Question 27

____________ include nematodes and tapeworms.

Answer 27

Internal parasites

Question 28

______________ include mosquitoes, ticks, and aphids.

Answer 28

External parasites

Question 29

are disease-causing microscopic parasites

Answer 29

Pathogens

Question 30

``` examples of pathogens: – ____________________ – ____________________ – ____________________ – ____________________ ```

Answer 30

- bacteria - viruses - fungi - protists

Question 31

is the feeding relationships among the various species in a community.

Answer 31

Trophic structure

Question 32

is the feeding relationships among the various species in a community.

Answer 32

Trophic structure

Question 33

A community’s trophic structure determines the passage of energy and nutrients from plants and other photosynthetic organisms such as – __________________ – __________________

Answer 33

herbavors | predators

Question 34

The trophic level that supports all other trophic levels consists of autotrophs, also called _______________.

Answer 34

producers

Question 35

All organisms in trophic levels above the producers are heterotrophs, or __________________.

Answer 35

consumers

Question 36

________ are called herbivores, which eat plants.

Answer 36

Primary consumers

Question 37

Above the level of primary consumers are

Answer 37

carnivores, which eat the consumers from the level below. | – Secondary consumerstertiary consumers quaternary consumers

Question 38

________ is lost as it moves each trophic level, limiting the number of trophic levels an ecosystem can sustain.

Answer 38

Energy

Question 39

Detritivores, which are often called scavengers, consume ______________, the dead material left by all trophic levels.

Answer 39

detrus

Question 40

which are often called scavengers, consume detrus the dead material left by all trophic levels.

Answer 40

Detritivores,

Question 41

Decomposers are _____________________, which secrete enzymes that digest molecules in organic material and convert them into inorganic forms.

Answer 41

prokraryotes and fungi

Question 42

are prokraryotes and fungi which secrete enzymes that digest molecules in organic material and convert them into inorganic forms.

Answer 42

Decomposers

Question 43

both Detritivores, and Decomposers

Answer 43

recycle nutrients and make them available to producers

Question 44

A _________ is a network of interconnecting food chains.

Answer 44

food web

Question 45

– In food Webs

Answer 45

– consumers may eat more than one type of producer | – several species of consumers may feed on the same species of producer.

Question 46

A food web shows mutliple interactions among producers, predators, and prey

Answer 46

which is a better representation of what occurs in nature.

Question 47

is concerned with the number of different species and their relative abundance in a community

Answer 47

Species diversity

Question 48

Species diversity is important in ecosystems because it makes them more productive and enables them to ____________________________________________.

Answer 48

rebound much faster if faced with a disturbance

Question 49

Although each of these woodlots has the same number of species, ______________________________________.

Answer 49

the more evenly distributed lot is more diverse

Question 50

have a disproportionate impact on diversity

Answer 50

Keystone species

Question 51

A _____________________ is a species whose impact on its community is larger than its biomass or abundance indicates and – occupies a niche that holds the rest of its community in place.

Answer 51

keystone species

Question 52

Examples of keystone species in marine ecosystems include – Pisaster sea stars because they keep the population of mussels in a marine environment in check. – WithoutPisaster,_______________________________ ____________________________________________.

Answer 52

mussels would completely dominate many marine habitats

Question 53

are events that damage biological communities.

Answer 53

Disturbance

Question 54

– Disturbances include

Answer 54

storms, fires, floods, droughts, overgrazing, or human activity.

Question 55

– The types, frequency, and severity of disturbances varies from

Answer 55

community to community.

Question 56

After a disturbance, an ________________________ follows.

Answer 56

ecological succession

Question 57

________________________ is the colonization of a species in a given habitat after a disturbance.

Answer 57

ecological succession

Question 58

– Primary succession begins in a virtually lifeless area with no soil. Ex: _____________________________

Answer 58

volcanos and glacial activity

Question 59

– Secondary succession occurs when a disturbance destroys an existing community but leaves the soil intact. – Ex:_____________________________________

Answer 59

fires and floods

Question 60

________________________: are organisms that have been introduced into non-native habitats by human actions and

Answer 60

invasive species

Question 61

– have established themselves at the expense of native communities. – The absence of natural enemies often allows rapid population growth of _____________

Answer 61

invasive species.

Question 62

Examples of invasive species include the deliberate introduction of

Answer 62

– rabbits into Australia | – cane toads into Australia.

Question 63

include essential elements and chemicals needed throughout different levels of an ecosystem. They include

Answer 63

biogeochemical cycles

Question 64

Biogeochemical cycle include

Answer 64

both biotic and abiotic components

Question 65

is the major ingredient of all organic molecules

Answer 65

carbon

Question 66

Carbon is found in: – ____________________ – ____________________ – _____________________________________

Answer 66

- atmosphere - fossil fuels - dissolved Carbon components in ocean

Question 67

The return of CO2 to the atmosphere by respiration closely balances _______________ The carbon cycle is affected by burning wood and fossil fuels.

Answer 67

its removal by photosynthesis.

Question 68

In the phophoric cycle: | Organisms require phosphorus for ___________________ _________________________________.

Answer 68

nucleic acids, phopholipids, and ATP

Question 69

In the phophoric cycle: | The phosphorus cycle does not have

Answer 69

an atmospheric component.

Question 70

In the phophoric cycle: | are the only source of phosphorus for terrestrial ecosystems.

Answer 70

Rocks

Question 71

In the phophoric cycle: | Plants absorb phosphate ions in the soil and build them

Answer 71

into organic compounds.

Question 72

In the phophoric cycle: | Phosphates are returned to the soil by ________________

Answer 72

decomposers

Question 73

In the phophoric cycle: _______________in aquatic ecosystems are typically low enough to be a limiting factor.

Answer 73

Phosphate levels

Question 74

________________________________ – essential to the structure and functioning of all organisms, and – a crucial and often limiting plant nutrient.

Answer 74

Nitrogen is an ingredient of proteins and nucleic acids,

Question 75

Nitrogen has two abiotic reservoirs: ___________________________________________ ___________________________________________

Answer 75

- the atmosphere is 80% nitrogen | - soil

Question 76

Although agricultural and other managed ecosystems are necessary to supply our needs,

Answer 76

we also depend on services provided by natural ecosystems.

Question 77

``` some Healthy ecosystems – _________________________________ – _________________________________ – _________________________________ – _________________________________ ```

Answer 77

- supply fresh water and food - recycle nutrients - decompose waste - regulate air quality

Question 78

converts N2 to compounds of nitrogen that can be used by plants and

Answer 78

Nitrogen fixation

Question 79

In Nitrogen fixation: | – is carried out by some _______________________.

Answer 79

bacteria