Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

George Biology > Ecosystems chp 23 only done > Flashcards

Ecosystems chp 23 only done Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what is decomposition

A

chemical process where compounds are broken down into smaller molecules or its constituent elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • define decomposer
  • give features of them
A
  • an organism that feeds on and breaks down dead animal/plant matter, turning organic material to inorganic
  • they are saprotrophs
  • primarily fungi and bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a saprotroph

A
  • obtain their energy from dead/waste organic material (saprobiotic nutrition)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how do decomposers digest food

A

digest food externally by secreting enzymes onto organic matter, this breaks the substances down and then the decomposer absorb these smaller molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are detritivores

A
  • help to speed up decaying process by feeding on detritus (dead/decaying matter)
  • examples include woodlice and earthworms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are some examples of nitrogen fixing bacteria

A
  • azotobacter (found in soil)
  • rhizobium (found In root nodules of leguminous plants)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what actualy is the process of nitrogen fixation

A
  • bacteria containing nitrogenase combine atmospheric nitrogen with hydrogen to produce ammonia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the benefits of rhizobium (nitrogen fixing bacteria) living within a plants roots

A
  • plant gains amino acids from rhizobium, produced by fixing nitrogen gas into ammonia
  • bacteria gain carbohydrates produced by plant, which they use an energy source
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what produces ammonia/ammonium ions in the nitrogen cycle

A

produced by nitrogen-fixing bacteria and decomposers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what producers nitries [NO2-] in the nitrogen cycle

A
  • formed by nitrifying bacteria from ammonia
  • plants cannot absord these
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what produces nitrates [NO3-] in the nitrogen cycle

A

produced by nitrifying bacteria from nitrites [NO2-]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is nitrification

A
  • process where ammonium compounds in soil are converted into nitrogen-containing molecules that can be used by plants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what type of reaction is nitrification and how does this effect it

A
  • oxidation reaction
  • only occurs I well aerated soil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the steps of nitrification

A
  • nitrifying bacteria oxidise ammonium compounds into [NO2-]
  • nitrobacter oxidises nitrites into nitrates [NO3-]
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are some examples of nitrifying bacteria

A
  • nitrosomonas
  • nitrobacter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is denitrification

A
  • process where nitrates in soil converted back to nitrogen gas
  • bacteria use nitrates as source of energy for respiration and nitrogen gas is realeased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what conditions must exist for denitrification to occur

A
  • only happens under anaerobic conditions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is ammonification

A

process by which decompress convert nitrogen containing molecules in dead/waste organic material into ammonium compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are some abiotic factors that have that can fix nitrogen

A
  • lighting strikes and the haber process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are some abiotic factors that have that can fix nitrogen

A

carbon dioxide in the atmosphere & dissolved in the seas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what can turn inorganic carbon to organic carbon-containing molecules

A
  • photosynthesis in plants
  • carbon is used to produce carbohydrates, proteins & lipids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how can carbon be trapped under ground

A
  • if dead organic matter is in a location where decomposers are not present the carbon it contains will not be released
  • forms fossil fuels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are the main reasons for the atmospheric rise in carbon dioxide levels

A
  • combustion of fossil fuels (releases carbon dioxide)
  • deforestation - removed massive parts of earths photosynthesising biomass, means less CO2 removed from atmosphere
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

define an ecosystem

A
  • made up of all living organisms that interact with one another in a defined area
  • also contains physical factors in regions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what 2 groups can factors that effect ecosystems be split into

A
  • biotic and abiotic factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what are biotic factors

A
  • living factors
  • can refer to interactions between living organisms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what are abiotic factors

A
  • non-living/physical factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what are some examples of abiotic factors

A
  • light (effect photosynthesis)
  • temperature (effects enzymes controlling metabolism)
  • water availability
  • oxygen availability
  • edaphic (soil) factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what are some different types of soil and what are there characteristics

A
  • clay: has fine particles, easily waterlogged
  • loam: has different-sized particles, retains water but doesn’t become water logged
  • sandy: well separated particles, doesn’t not retain water well, is eroded easily
30
Q

what are trophic levels

A
  • stages in food chain/web
31
Q

what is the 1st trophic level

A
  • producer
32
Q

what is the 2nd trophic level

A
  • primary consumer
33
Q

what is a meant by a producer

A
  • organism that converts light energy into chemical energy via photosynthesis
34
Q

what are primary, secondary, tertiary and quaternary consumers

A
  • primary = animal that eats producer
  • secondary = animal that eats primary consumer
  • tertiary = animal that eats secondary consumer
  • quaternary = animal that eats tertiary consumer
35
Q

what is biomass

A
  • the mass of living material present in a particular place/organism
36
Q

how do you calculate biomass

A
  • biomass present in each organism x number of organisms in that trophic level
37
Q

what must be excluded from biomass mass

A

the mass of water in the organism

38
Q

how can the problem of water influencing biomass be overcome

A
  • by finding dry mass (mass of organism without water)
39
Q

what is a problem with finding dry mass of an organism

A
  • organisms have to be killed in order to be dryed
  • only small amount of organism is taken (may not represent whole organism)
40
Q

what is biomass measured in

A
  • measured in kg or grams per square metre (kg or g m^-2) for areas of land
  • in kg or g per cubed metre for areas of water (kg or g m^-3
41
Q
  • what is the trend of biomass as you go up trophic levels
  • why is this
A
  • biomass is always less that trophic level below
  • small proportion of food ingested is converted into new tissue
  • some is excreted, some is used in respiration, some is made into inedible tissues
42
Q
  • what is ecological efficiency
  • what is the equation to find it
A
  • efficiency with which biomass/energy is transferred from one trophic level to the next
  • (energy/biomass available after transfer) / (energy/biomass available before transfer) x 100
43
Q

what percentage of sunlight is actually converted into chemical energy by producers

A
  • 1 - 3 %
44
Q

why are producers so inefficient at converting sunlight to chemical energy

A
  • roughly 90% is reflected
  • some is transmitted through leaf
  • some is unusable wavelength
  • other factors may limit photosynthesis
  • proportion or energy is lost as it used for photosynthesis and respiration reactions
45
Q

what is meant by gross product in reference to biomass

A
  • rate at which energy is incorporated into organic molecules by an ecosystem
46
Q

what is the calculation to find net primary product for plants

A
  • gross primary product - respiration losses
47
Q

what is net primary productvity

A
  • rate at which energy is transferred into the organic molecules that make up the new plant biomass
48
Q

what is the difference between inter and intra

A
  • inter = between species
  • intra = between organisms in species
49
Q

define succession when talking about ecosystems

A

process where ecosystems change overtime from nothing to climax communities

50
Q

define primary succession

A
  • occurs on area of land that has been newly formed/exposed
  • no organic material has been there before
51
Q

define secondary succession

A
  • occurs on areas of land where soil is present
  • organic material has been there before but there is none currently

such as forest after fire

52
Q

give some examples of where primary succession may still occur

A
  • volcanoes erupting, depositing lava and creating rock
  • sand blows creating new sand dunes
  • glaciers retreat exposing rock
53
Q
  • define seral stages
  • what can be seen at any given stage

plural: sere

A
  • steps of succession
  • at each stage key species are seen that changed the abiotic factors to make it more suitable for other species
54
Q

what are the main serial stages

A
  • pioneer community (e.g. mosses, lichen)
  • intermediate community (grasses, shrubs)
  • climax community (large trees)
55
Q

how do pioneer communities get to uninhabitable environments

A
  • seeds are carried by animals or wind and deposited to environments
56
Q

what adaptations do pioneer species have that allow them to live in extreme environments

A
  • produce large quantities of seeds/spores
  • seeds germinate rapidly
  • can photosynthesis
  • tolerant to extreme environments
  • can fix nitrogen from air
57
Q
  • define humus
  • how is it produced
A
  • organic component of soil
  • as pioneer species die and decompose they deposit organic products into soil
58
Q

How does the climax community change after being established

A
  • the community is in stable state
  • will show very little change over time
59
Q

What is the trend in biodiveristy throughout all the seral stages

A
  • biodiversity reaches a peak in mid-succession
    ^after this tends to decrease as dominant species out compete others
60
Q

what are the differences between animal and plant succession

A
  • animal succession tends to be slower as must move in from neighbouring areas
    ^even harder if land is isolated
  • secondary consumers must wait till sufficent habitats and food supplies have been attained to move in
61
Q

define plagioclimax

A
  • the final stage reached after succession has been halted artificially by humans
62
Q

what are some examples of where humans can stop succession

A
  • grazing and trampling of vegetation by animals
  • removing existing vegetation to plant crops
  • burning to clear forest
63
Q

what is the equation for estimated number of individuals in population for plants and slow moving animals

A
  • number of individuals in sample / area of sample
64
Q

How can estimated population size be calculated from capture-mark-release-recpature

A
  • number of individuals in first sample x number of individuals in second sample / number of recaptured marked individuals
65
Q

outline the process of mark-capture-release-recapture

A
  • capture as many animals as possible, mark them and release
    ^mark cannot effect success of animals
  • leave population to redistribute themselves through habitat
  • recapture as many individuals as possible
66
Q

important process in carbon cycle

A

respiration
photosyntehsis
combustion

67
Q

effect of plants on carbon cycle

A

take CO2 from air via photosynthesis
producer CO2 via respiration
death transfer carbon into soil

68
Q

how do animals affecct carbon cycle

A

respire to let CO2 into air
feed on organic matter to take into carbon
death transfer carbon into soil

69
Q

how do decomposers affect carbon cycle

A

respire to give out CO2

70
Q

How do fossil feuls affect carbon cycle

A

combusted to give out lots of CO2 into atmosphere

George Biology (71 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions