ecology Flashcards

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1
Q

population definition

A

the number of organisms of the same species living in the same area

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2
Q

biodiversity definition

A

all the organisms that are interdependent on eachother and the environment in which they live eg living organisms in a rainforest

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3
Q

habitat definition

A

the area where and organism lives

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4
Q

community definition

A

the number of organisms of all the species living in the same area

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5
Q

decomposer definition

A

an organism that gains energy by feeding on dead organisms and breaking them down eg fungi and bacteria

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6
Q

biotic factor

A

living factors that may affect the distribution of organisms eg predation of mice by owls, competition for sunlight in a field of sunflowers

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7
Q

trophic level definition

A

the level of the food chain that the organism is feeding at. The producer is always at trophic level 1

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8
Q

food chain definition

A

shows what eats what in a community

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9
Q

food web definition

A

shows how food chains interact in a community

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10
Q

pyramid of biomass definition

A

shows the dry mass of individuals at each stage in a food chain

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11
Q

consumer definition

A

an organism that gains energy by eating another organism

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12
Q

abiotic factor definition

A

non living factors that may affect the distribution of plants and animals

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13
Q

examples of biotic factors

A

predation
food availability
competition

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14
Q

how is wind speed measured

A

an anemometer

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15
Q

how is ph measured

A

soil tests or a ph probe

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16
Q

how is light measured

A

light meter

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17
Q

how is temperature measured

A

thermometer

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18
Q

how is water/ moisture levels measured

A

weigh soil sample
dry sample in oven
reweigh sample
calculate change in mass
calculate the % of mass lost

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19
Q

how to calculate % soil moisture

A

change in mass/original mass X100

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20
Q

sampling method

A

-use quadrat
-place quadrat along line transect or use random sampling by throwing quadrat over the shoulder or using coordinates
-move quadrat and place at different distances
-use a key to identify species
-calculate percentage cover of species or count number of species
-record results
-repeat

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21
Q

what do food chains show

A

the feeding relationships which transfer energy and nutrients between several different organisms

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22
Q

what’s an issue with pyramids of numbers

A

they can be misleading as they don’t take size of the individuals into account 

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23
Q

name an advantage of pyramids of biomass over a pyramid of numbers

A

accounts for differing sizes of individual organisms, therefore giving a more accurate picture of energy in the ecosystem 

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24
Q

name an advantage of pyramids of numbers over pyramids of biomass

A

They are easier to calculate as you just count the number of individuals. You don’t need to kill them to calculate their dry mass and you do for biomass.

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25
Q

hi, is energy lost between the Sun and plant

A

-Light is reflected off of the leaf
-Light passes through the leaf and Mrs chloroplasts
-Light hits the ground rather than the leaf

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26
Q

how much energy is transferred between trophic levels?

A

Approximately 10 to 20%

27
Q

why is energy lost in between the trophic level

A

-Not all food available is eaten e.g. bones and fur
-Not all food is digested as egested as faeces
-Heat and respiration, respiration provides energy for movement growth and reproduction

28
Q

what is the equation for energy efficiency?

A

energy at tropic level/energy at previous tropic level X100

29
Q

why are warm temperatures needed for decay

A

So that decomposers can respire aerobically to breakdown organic material

30
Q

how do decomposers work?

A

They are saprophytic and breakdown dead organic matter by secreting enzymes onto it to digest it extracellularly and then absorb the nutrients

31
Q

what are the best conditions for decomposition?

A

-Warm temperatures
-Adequate moisture
-Large surface area and decomposing organism

32
Q

describe photosynthesis purpose in the carbon cycle

A

Carbon dioxide is converted into glucose and other organic carbon compounds

33
Q

describe the process of feeding in the carbon cycle

A

Carbon transfers from plants to animals or animals to animals when eating

34
Q

Describe the process of respiration in the carbon cycle

A

Carbon dioxide is returned to the atmosphere by plants, animals and decomposers

35
Q

describe the process of decomposition in the carbon cycle

A

Bacteria and fungi breakdown carbon containing compound and release carbon dioxide by respiration

36
Q

Describe the process of fossilisation in the carbon cycle

A

Plants and animals which don’t decay are preserved over a long time becoming fossil feels

37
Q

describe the process of combustion in the carbon cycle

A

Carbon dioxide is released when fossil fuels are burned

38
Q

describe the process of excretion in the carbon cycle

A

The process of expelling waste matter from the body eg urination

39
Q

Describe the process of egestion in the carbon cycle

A

The process of expelling undigested foods such as faeces

40
Q

describe nitrogen fixing bacteria’s role in the nitrogen cycle

A

-They carry out nitrogen fixation which converts nitrogen gas to nitrates
-They’re found in the soil and root nodules of legumes
-They use the glucose the plant produces as a food source and in turn, they provide the plants with nitrates to grow

41
Q

describe nitrifying bacteria role in the nitrogen cycle

A

-These bacteria perform nitrification which converts ammonia compound in the soil into nitrates

42
Q

describe the role of denitrifying bacteria in the nitrogen cycle

A

-These bacteria perform denitrification converting nitrates in the soil into nitrogen gas
-These bacteria like waterlogged conditions which are anaerobic

43
Q

describe the role of bacteria and fungi in the nitrogen cycle

A

-Bacteria and fungi are decomposers
-These microbes carry out decomposition breaking down protein in dead plants and animals into ammonia.
-This is essential to maintain the cycle

44
Q

what is a root hair cell?

A

Specialised cells in the root that are adapted for absorption by having fingerlike extensions providing a large surface area for increased absorption of water, nitrates and other minerals

45
Q

how , are nitrates taken into the cell?

A

-Nitrates are taken into the cell by active transport
-This process requires energy
-It transports the nitrates against a concentration gradient from a low concentration in the soil to high concentration in the cell
-Cells make the energy needed for active transport during respiration
-Cells need oxygen for aerobic respiration to produce energy to move the nitrates against the concentration gradient

46
Q

why is there poor plant growth in water logged soil?

A

-In waterlogged soil, there is less oxygen
-Meaning less respiration
-Less energy in root hair cells
-Less active uptake of nitrates
-Less protein made in plants
-Less plant growth
-Denitrifying bacteria thrives and waterlogged conditions meaning they will remove nitrates from the soil

47
Q

Where are the stores of nitrogen?

A

-nitrogen gas
-Nitrates in the soil
-Protein in plants
-Protein in animals

48
Q

why is animal manure used in fertiliser?

A

Nitrates are excreted from animals in their urine and egested in their faeces

49
Q

Describe active uptake in aerated soils

A

-more oxygen in soil means
-More respiration
-More energy in root hair cells
-More active transport of nitrates
-More protein produced
-More growth

50
Q

what minerals are found in fertilisers?

A

-nitrates
-Calcium needed for plant cell walls
-Magnesium needed to make chlorophyll

51
Q

how can buying fertiliser be an investment for farmers?

A

Increases the crop yield

52
Q

describe advantages of artificial fertilisers

A

-Easier to spread
-Mineral content can be controlled

53
Q

describe disadvantages of artificial fertilisers

A

-Soil structure can deteriorate
-Easily washed off

54
Q

describe advantages of natural fertilisers

A

-Contains organic content so add humus and structure to the soil
-Cheaper

55
Q

describe disadvantages of natural fertilisers

A

-Smells bad and is messy
-Exact mineral content is unknown

56
Q

Describe the process of eutrophication

A

-addition of nutrients to water from sewage and fertiliser run-off
-leads to increase in growth of aquatic plants, e.g. algae
-algae grows to form algal bloom
-algal bloom blocks the light from reaching plants that are lower down causing them to die
-The dead plants are decomposed by aerobic bacteria
-The bacteria uses up the dissolved oxygen in the water
-The fish and other animals die due to lack of oxygen

57
Q

how can eutrophication be reduced?

A

By increasing environmental awareness of farmers to encourage better control of fertiliser and more secure storage of manure and slurry

58
Q

what is leach?

A

The run-off into lakes

59
Q

how, has the carbon cycle changed in the past 150 years?

A

-Increased combustion of fossil fuels add more carbon dioxide to the atmosphere
-Increase deforestation means less carbon dioxide is absorbed by plants in photosynthesis

60
Q

name the effects of global warming

A

-Climate change
-Polar ice caps are melting
-Sea levels rise and there is flooding
-More land becomes desert
-Loss of habitats

61
Q

how to prevent global warming

A

-Plant more trees
-renewable fuels instead of fossil fuels 
-Reduce deforestation

62
Q

how does human activity damage biodiversity?

A

-Deforestation
-Burning fossil fuels
-Using excess fertilisers

63
Q

How to slow the effects of human activity on biodiversity

A

-sustainable wood:
* only a small number of large trees are harvested at a time
* saplings planted so this creates reforestation
* harvesting of the same area does not happen again until medium trees have grown to become large

-International measures:
* 1997 Kyoto protocol
* Paris in 2015- 195 countries agreed to a legally binding global climate change deal to attempt to reduce global warming