Ch.19 Ecosystems Flashcards
Habitat (生境) is the place where organisms live. Each habitat has a well-_________ set of _________ conditions (e.g. soil types and temperature).
defined; physical
Ecology (生態學) is the study of the inter-relationships between organisms and the inter-relationships between organisms and their ____________.
environment
Levels of organization:
species → _________ → _________ → _________ → ______ → biosphere
species (物種) → population (種羣) → community (羣落) → ecosystem (生態系) → biome (生物群系) → biosphere (生物圈)
In an ecosystem, the cycling of materials, interactions between organisms and their physical environment lead to the flow of ______. These features maintain a self-_________, s______, and yet d_________ ecosystem.
energy; supported; stable; dynamic
Which two components made up an ecosystem?
- abiotic factors (non-living components)
- biotic community (living component)
(1):abiotic factors (2):biotic community Species diversity (\_\_) Oxygen level (\_\_) Habitat (\_\_) Rainfall and humidity (\_\_)
Species diversity (2)
Oxygen level (1)
Habitat (2)
Rainfall and humidity (1)
(1):abiotic factors (2):biotic community Dominant species (\_\_) Niche (\_\_) Salinity (\_\_) Light intensity and day length (\_\_)
Dominant species (2)
Niche (2)
Salinity (1)
Light intensity and day length (1)
What is the meaning of “niche”?
A niche(生態位) is the role that an organism plays in its environment.
Species 1 gains benefit from species 2 while species 2 is harmed by species 1. What is the type of relationship between them?
Predation (捕食) [ 1=predator(+); 2=prey(−) ] or Parasitism (寄生) [ 1=parasite(+); 2=host(−) ]
Both species 1 and 2 gains benefit from each other. What is the type of relationship between them?
Mutualism (互利共生)
T/F: In parasitism, both species of organisms are harmed by each other.
F
In commensalism(偏利共棲), both species of organisms are harmed by each other.
In parasitism/predation, Species 1 gains benefit from species 2 while species 2 is harmed by species 1.
In predation, the populations of both the prey and the predator sometimes follow a cycle. The change in the population of the p______ is always lagging behind that of the p______.
predator; prey
Is interspecific competition or intraspecific competition usually more intense? Explain.
Intraspecific competition(種內競爭) is usually more intense than interspecific competition(種間競爭). Individuals of the same species have the same niche and same needs.
_________ _________ is the series of changes in the composition of a community over a period of time.
Ecological succession (生態演替)
Process of primary succession:
- After the retreat of the glacier, ______ ______ are exposed. Wind brings ______ spores to the rocks to form the _________ _________. The ______ ______ of the lichens are decomposed to become organic matter. The small rock particles and the organic matter gradually form the ______.
- ______, ______ and grass start to grow in the soil and become the dominant species.
- Dead, decaying plants and animals, as well as animal waste form ______ which further enriches the soil for the growth of ______.
- The soil becomes thick and rich in _________ to support the growth of trees. The habitat turns into a _________ that attracts increasing numbers of animals. A _________ _________ is reached as species diversity reaches a maximum.
- barren rocks; lichen; pioneer community(先鋒羣落); dead bodies; soil
- Mosses; ferns
- humus (腐殖質); shrubs
- nutrients; woodland; climax community (頂級羣落)
Complete the table of primary succession:
Where it takes place: in ______ areas
Pioneer community: ______
Time needed to reach climax community: ( shorter / longer )
Where it takes place: in barren areas (where no
organisms and soil were present before)
Pioneer community: lichens
Time needed to reach climax community: longer
Complete the table of secondary succession:
Where it takes place: in ______ areas
Pioneer community: g______ and f______
Time needed to reach climax community: ( shorter / longer )
Where it takes place: In areas where organisms were
present before but are now barren
Pioneer community: grasses and ferns (because soil is already present)
Time needed to reach climax community: shorter (because seeds, roots and underground vegetative organs of plants are present in the soil)
Where does secondary succession take place?
Secondary succession(次生演替) take places in areas where organisms were present before but are now barren.
What is the pioneer community of secondary succession? Explain.
Grasses and ferns.
It is because soil is already present.
Why the time needed to reach climax community in secondary succession is shorter than that of primary succession?
It is because seeds, roots and underground vegetative organs of plants are present in the soil.
[T/F] Energy in most ecosystems ultimately comes from the sun.
T
[T/F] Energy flows in an ecosystem in the form of physical energy in food from producers to consumers.
F
Energy flows in an ecosystem in the form of chemical energy in food from producers(生產者) to consumers(消費者).
Producers are _________ that can make their own food; consumers are _________ that feed on other organisms.
autotrophs (自養生物); heterotrophs (異養生物)
A ______ ______ shows the sequence of organisms in a particular feeding relationship. It also shows the directions of energy and material flow from one organism to another.
food chain (食物鏈)
According to food chain, fill in the blanks.
Wolf [Role: _________ consumer; Trophic level: ______]
↑
Fox [Role: _________ consumer; Trophic level: ______]
↑
Rabbit [Role: _________ consumer; Trophic level: ______]
↑
Grass [Role: _________; Trophic level: ______]
Wolf [Role: tertiary consumer; Trophic level: fourth]
↑
Fox [Role: secondary consumer; Trophic level: third]
↑
Rabbit [Role: primary consumer; Trophic level: second]
↑
Grass [Role: prodecer; Trophic level: first]
[T/F] A food chain shows all the possible feeding relationship among selected organisms in an ecosystem.
F
A food chain(食物鏈) shows the sequence of organisms in a particular feeding relationship.
A food web(食物網) shows all the possible feeding relationships among selected organisms in an ecosystem as most animals feed on more than one type of organism.
Energy flows and losts along ______ ______ in an ecosystem.
trophic levels (營養級)
A large proportion of energy is lost to the surroundings when it is transferred from one trophic level to another. Name two ways of energy lost in ecosystem.
- uneaten materials
- undigested and egested materials
- excretory products
- heat during respiration
Why there is rarely a food chain consisting of more than five trophic levels?
With fewer trophic levels, less energy is lost.
In other words, a shorter food chain can support more consumers than a longer food chain.
Decomposers are s_________. They secrete digestive enzymes outside their bodies to break down dead organic matter by decomposition.
saprophytes (腐生生物)
Decomposers are important in material cycling:
- ( Physical / Chemical ) energy stored in the dead organic matter is transferred to the decomposers.
- ( Organic / Inorganic ) nutrients released from the breakdown of dead organic matter are absorbed by decomposers and plants for growth.
- Decomposers carry out respiration to release ( carbon dioxide / oxygen ) back to the atmosphere.
- {Chemical} energy stored in the dead organic matter is transferred to the decomposers.
- {Inorganic} nutrients released from the breakdown of dead organic matter are absorbed by decomposers and plants for growth.
- Decomposers carry out respiration to release {carbon dioxide} back to the atmosphere.
[T/F] Pyramid of numbers is a bar diagram showing the total dry mass of organisms at all trophic levels in a given unit area at a particular point of time.
F
Pyramid of numbers is a bar diagram showing the number of organisms at each trophic level. Area of each bar is proportional to the number of organisms at that trophic level.
Size of the bars ( increases / decreases ) up the trophic levels of the pyramid of numbers, while it may ( increases / decreases ) up in the case of an inverted pyramid.
Size of the bars {decreases} up the trophic levels of the pyramid of numbers, while it may {increase} up in the case of an inverted pyramid.
Size of the bars of pyramid of numbers decreases up the trophic levels because:
- ( less / more ) energy is available to organisms at higher trophic levels;
- a predator is usually ( larger / smaller ) in size than its prey, and hence requires ( less / more ) energy to maintain its life.
Size of the bars of pyramid of numbers decreases up the trophic levels because:
- {less} energy is available to organisms at higher trophic levels;
- a predator is usually {larger} in size than its prey, and hence requires {more} energy to maintain its life.
Pyramid of biomass is a bar diagram showing the total ______ ______ of organisms at all trophic levels in a given unit area at a particular point of time.
dry mass
Explain the presence of an inverted pyramid of biomass.
- In a pyramid of biomass, the lifespans of organisms are not considered.
- Organisms at a lower trophic level may have a much higher reproduction rate and shorter lifespan (i.e. a higher turnover rate) than organisms at a higher trophic level.
[T/F] The amount of energy stored in an organism is usually proportional to the amount of living material in its body.
T
The energy flow to _________ is not considered in ecological pyramids.
decomposers
- Carbon transfer between trophic levels and decomposers:
- Carbon, in the form of _________ matter, is transferred from producers to consumers by _________
- Organic matter in ______ ______ or ______ materials of organisms is used as food by decomposers
- organic; feeding
- dead bodies; waste
- Return of carbon dioxide to the atmosphere and oceans:
- _________ of all organisms and ___________ by decomposers
- Combustion of ______ ______
- Reaction of carbonates in _________ with acids in water or when they are heated under high pressure during _________ _________
- respiration; decomposition
- fossil fuels
- limestone (石灰石); volcanic eruption
- Removal of carbon dioxide from the atmosphere and oceans:
- Carbon dioxide are taken up by producers for ___________
photosynthesis
Addition of nitrogen to the soil:
- Decomposition by decomposers converts nitrogen in organic waste and dead bodies of producers and consumers to _________ _________
- Nitrification (硝化) by nitrifying bacteria (硝化細菌) turns ammonium compounds into nitrites and then nitrates
- Lightning (閃電) turns nitrogen in the atmosphere into nitrogen oxides, which is then dissolved in rainwater to form nitrates in the soil
- Nitrogen fixation (固氮) by nitrogen fixing bacteria (固氮細菌) converts nitrogen in soil air to ammonium compounds
- ammonium compounds
- Addition of nitrogen to the soil:
- Decomposition by decomposers converts nitrogen in organic waste and dead bodies of producers and consumers to _________ _________
- _________ by _________ bacteria turns ammonium compounds into nitrites and then nitrates
- _________ turns nitrogen in the atmosphere into nitrogen oxides, which is then dissolved in rainwater to form _________ in the soil
- Nitrogen fixation (固氮) by nitrogen fixing bacteria (固氮細菌) converts nitrogen in soil air to _________ _________
- ammonium compounds
- Nitrification (硝化); nitrifying
- Lightning (閃電); nitrates
- ammonium compounds
- Removal of nitrogen from the soil
- _________ are taken up by producers
- ____________ by denitrifying bacteria in poorly aerated soil changes nitrates in the soil into _________ ______
- Nitrates
- Denitrification (反硝化); nitrogen gas
What are the roles of producers in energy flow?
Capture light energy by photosynthesis and convert it to the chemical energy stored in organic compounds.
What are the roles of consumers in energy flow?
Transfer chemical energy along the food chain in the form of food
What are the roles of decomposers in energy flow?
Transfer chemical energy from the dead bodies and organic waste to the bodies of the decomposers, which may serve as food for consumers.
[The roles of producers in material cycling (in carbon & nitrogen cycle):
- Take in c______ and _________ in the form of ( organic / inorganic ) compounds from the physical environment and convert them to ( organic / inorganic ) compounds
- Release carbon into the physical environment in the form of ______ _________ through ( photosynthesis / respiration / decomposition )
- Release _________ compounds to the soil as their dead bodies are ___________ by decomposers; the ammonium compounds are converted to n______ and n______ by nitrification
- Take in {carbon} and {nitrogen} in the form of {inorganic} compounds from the physical environment and convert them to {organic} compounds
- Release carbon into the physical environment in the form of {carbon dioxide} through {respiration}
- Release {ammonium} compounds to the soil as their dead bodies are {decomposed} by decomposers; the ammonium compounds are converted to {nitrites} and {nitrates} by nitrification
The roles of consumers in material cycling (in carbon & nitrogen cycle):
- _________ carbon and nitrogen in the form of
( organic / inorganic ) matter along the food chain
- Release carbon into the physical environment in
the form of ______ _________ through ( photosynthesis / respiration / decomposition )
- {Transfer} carbon and nitrogen in the form of {organic} matter along the food chain
- Release carbon into the physical environment in
the form of {carbon dioxide} through {respiration}
The roles of decomposers in material cycling (in carbon & nitrogen cycle):
- _________ carbon into the ( biotic / abiotic ) environment in the form of carbon dioxide through respiration
- ______ ______ organic waste and the dead bodies of producers and consumers, thus returning _________ in the form of ( organic / inorganic ) compounds into the physical environment for _________ by plants
- {Release} carbon into the {abiotic} environment in the form of carbon dioxide through respiration
- {Break down} organic waste and the dead bodies of producers and consumers, thus returning {nitrogen} in the form of {inorganic} compounds into the physical environment for {absorption} by plants
