Ecosystems Flashcards

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1
Q

What is the difference between a community and a population?

A

A population is all the organisms of a particular species living in the same area whereas a community is all the interdependent populations of organisms in an area

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2
Q

What forms an ecosystem?

A

Organisms and the environment where they live

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3
Q

What is the calculation for an estimate for a population size from a quadrat?

A

POPULATION SIZE = NUMBER OF ORGANISMS IN ALL QUADRATS X TOTAL SIZE OF AREA/TOTAL AREA OF QUADRATS

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4
Q

What are some examples of abiotic factors?

A
  • pH
  • Temperature
  • Oxygen levels
  • Light intensity
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5
Q

What are 2 examples of biotic factors?

A
  • Competition

- Predators

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6
Q

What does a food web show?

A

The feeding relationships between the organisms in a community

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7
Q

What is the difference between an organism, population, community and ecosystem?

A
  • Organism - a single living organism
  • Population - all the organisms of the same species in an area
  • Community - all the populations in an area
  • Ecosystem - all the living organisms (the community) and the non-living components in an area
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8
Q

What is a pollutant?

A

Energy or a chemical substance that has a harmful effect on living organisms

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9
Q

What might plants compete for?

A
  • Light
  • Space
  • Water
  • Nutrients
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10
Q

What might animals compete for?

A
  • Food
  • Mates for reproduction
  • Territory
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11
Q

Why do very few plants grow beneath a canopy?

A

Very little sunlight so plants unable to compete with trees for sunlight

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12
Q

What is intraspecific competition?

A

Same species competing for the same resource

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13
Q

What is interspecific competition?

A

Members of different species competing for the same resource

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14
Q

What is a niche?

A

The role of a species within a particular ecosystem

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15
Q

Around how much energy does the Earth capture from the Sun via photosynthesis each year?

A

3X10^20 joules

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16
Q

What is the energy flow in organisms?

A

PRODUCER -> PRIMARY CONSUMER (HERBIVORE) -> SECONDARY CONSUMER (CARNIVORE)

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17
Q

What are trophic levels?

A

Feeding levels

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18
Q

What is a parasite?

A

An organism that feeds on another organism (host) while they are living together which harms the host but benefits the parasite

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19
Q

What is mutualism?

A

When 2 organisms live closely together in a way that benefits them both

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20
Q

Describe the mutualism between a shark and small fish

A
  • The cleaner small fish benefit by getting food

- Shark benefits from loss of dead skin and parasites

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21
Q

Why is the pyramid of biomass a pyramid?

A
  • Because it shows how energy is transferred from the food chain to the environment at each trophic level
  • Helps to explain why there is a maximum length of food chain in an ecosystem
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22
Q

How do some species of lichen act as air pollution indicators?

A
  • They grow on trees and buildings and have a mutualistic relationship between fungus + alga
  • For the last 20 yrs only found in industrial areas
  • They are only lichen to tolerate air pollution with sulfur-containing gases from burning fossil fuels
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23
Q

How are blackspots on rose leaves indicators of air pollution?

A
  • It is a fungus and pathogen of roses
  • Cannot grow where there is a lot of sulfur pollution
  • Roses growing in cities rarely suffer from blackspot infection
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24
Q

What can water pollution be caused by?

A

Poisonous substances released by factories such as mercury or detergents, or fertilisers and sewage

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25
Q

What does eutrophication encourage?

A

The rapid growth of algae and plants

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26
Q

What is negative about algae and plants growing in the water due to eutrophication?

A

They reduce the O2 concentration in the water, killing many animals living in it

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27
Q

How can you calculate the efficiency of energy transfer?

A

ENERGY TRANSFERRED TO BIOMASS/TOTAL ENERGY SUPPLIED TO ORGANISM X 100

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28
Q

How are stonefly larvae water pollution indicators?

A

Can only live in water that contains lots of O2, so show unpolluted water

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29
Q

How are bloodworms indicators of water pollution?

A

Can live in water that contains little oxygen, so are found in polluted water

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30
Q

How much energy from the Sun to the Earth is lost by reflection or used to evaporate water/heat up the soil?

A

About 98%, so only 2% gets trapped by the producer

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31
Q

Where is energy lost at each trophic level?

A

By heating, urine, faeces and respiration

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32
Q

Describe how to carry out random sampling using a quadrat

A
  • Place x and y axis along floor using measuring tape
  • Random number generator for coordinates
  • Place quadrat at corner of coordinate (1m^2)
  • Count biotic factor in quadrat
  • Repeat 10 times at different random coordinates for accuracy
  • Calculate mean value
  • Find out area of whole space
  • TOTAL AREA (M^2)/AREA OF ONE QUADRAT (M^2) X MEAN NUMBER OF ORGANISMS IN ONE QUADRAT
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33
Q

Describe how to carry out sampling using a belt transect

A
  • Place a piece of rope/tape measure across the habitat you are looking at
  • Use a quadrat to count the number of organisms at intervals (e.g. every 1/2m) on the transect to see how the number of organisms change along the line
  • Repeat this 3 times by moving the line across the habitat and repeat the whole process for validation
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34
Q

How is fish farming beneficial?

A

As human population increases, fish intake increases and people overfish; fish farming aims to produce more fish and so reduce overfishing of wild fish

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35
Q

How does fish farming cause problems?

A
  • Many fish are kept in a relatively small space and so are cramped and parasites/disease spread more easily between fish so need to be treated frequently to keep them healthy
  • Uneaten food and faeces from the fish sink to the bottom of the water which can change conditions and may harm the fish living there
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36
Q

What are indigenous/native species?

A

Organisms that have always been in an ecosystem

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37
Q

Why are some non-indigenous species sometimes introduced to areas?

A

To reduce the number of another species that has got out of control

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38
Q

What is eutrophication?

A

The addition of more nutrients to an ecosystem than it normally has

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39
Q

Describe how eutrophication can affect an aquatic ecosystem

A
  • Fertiliser added
  • Heavy rain washes fertiliser off
  • Nitrates and phosphates dissolve in soil water
  • Nitrates and phosphates not taken up by plants are washed into stream or river
  • High nitrate and phosphate concentrations in the water encourages plants and algae to grow rapidly
  • Surface plants block sunlight, so plants in the water die and stop producing oxygen through photosynthesis
  • Bacteria that break down dead materials increase in numbers and use up more oxygen from the water
  • Oxygen concentration of water decreases
  • Aquatic animals like fish die due to lack of oxygen
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40
Q

What is fish farming?

A

Growing one kind of fish in an area

41
Q

What are pooters used for?

A

To suck small insects from vegetation without harming them

42
Q

What can nets be used for when estimating insect population sizes?

A

Can be swept through grass, bushes, streams or ponds (small insects are collected)

43
Q

Describe a pit-fall trap

A
  • Walking/crawling insects from the soil surface or leaf little can be attracted to a jar with jam or meat inside
  • Make a soil slope around the jar
  • Wood/stone cover so birds/predators don’t eat them
  • Small stones to raise it to allow insects to get in
44
Q

Describe a tullgren funnel

A

-Heat source above funnel and beaker with alcohol at bottom
Funnel with soil and leaf litter on top of beaker with metal gauze-
Small insects and other arthropods move done away from the heat source towards the cooler moist conditions

45
Q

What is the moral reason for maintaining biodiversity?

A

Humans should respect other living organisms

46
Q

What is the aesthetic reason for maintaining biodiversity?

A

People enjoy seeing the variety of living organisms that live in different habitats?

47
Q

Why is ecosystem structure a reason for maintaining biodiversity?

A

Some organisms maintain an important role in ecosystems as microorganisms in decay processes and nutrient recycling. If we lose species, food chains become more unstable

48
Q

Why is usefulness a reason for maintaining biodiversity?

A

Some species are particularly useful to humans, like plants that produce life-saving drugs or wild varieties of plants grown for crops as a source of genes if the environment changes

49
Q

What is reforestation?

A

Replanting forests where they have been destroyed, like to create farmland

50
Q

What are the advantages of reforestation?

A
  • Restores habitats for endangered species
  • Reduces the concentration of carbon dioxide in the air as the trees photosynthesise
  • Tree roots bind the soil together and reduce the effects of soil erosion
  • Affects local climate, such as reducing temperature variation
51
Q

What is food security?

A

Having access to enough safe and healthy food at all times

52
Q

What do healthier countries prefer to eat?

A

Meat and fish

53
Q

What do some think we should eat to help protect the environment?

A

More vegetable protein as opposed to meat and fish protein

54
Q

Why is growing food from crops using agricultural inputs (fertilisers) an issue?

A
  • Most of the fertiliser is made using chemical processes that need energy and release CO2, raising concerns about sustainability
  • Increase eutrophication
55
Q

How does growing plants for biofuels reduce carbon emissions?

A

The carbon released by burning a biofuel is only the amount removed from the air by the crop as it grew and so does not contribute to rising levels of carbon emissions

56
Q

What is wrong with biofuels?

A

Land that could have been used to grow crops was used to grow biofuels

57
Q

What are the soft tissues of organisms decayed by soon after death?

A

Decomposers

58
Q

Where do decomposers grow best?

A

In moist and warm conditions, and many of them need oxygen

59
Q

What do most methods of food preservation rely on?

A
  • Reducing temperatures (freezers)
  • Reducing water content (salting and drying)
  • Irradiation of packaged foods (to kill decomposers)
  • Reducing oxygen (storing foods in oil)
60
Q

What are foods that easily decay often packaged in?

A

An unreactive gas like nitrogen

61
Q

What forms compost?

A

Waste garden material in heaps that have been well-decayed

62
Q

What does the decay process allow for composts?

A

To be absorbed easier by plants

63
Q

What does compost increase?

A

Soil fertility

64
Q

How do you calculate rate of decomposition?

A

MASS LOST (G)/NUMBER OF DAYS

65
Q

What is decay?

A

The break down/digestion of materials by microorganisms

66
Q

How does salting foods work?

A

It causes water to move out of bacterial cells by osmosis so there is not enough water in the microorganism cells for them to grow

67
Q

What do ions form when they decompose?

A

Ammonia

68
Q

Why do we need nitrogen?

A

Contains amino acids that help make proteins in our bodies

69
Q

What is bioaccumulation?

A

Heavy metals or chemicals that stay in your fat

70
Q

How does vinegar help in food preservation?

A

It is an acid and so lowers the pH so enzymes of microbes cannot work

71
Q

What do compost activators contain?

A

Bacteria and fungal spores

72
Q

What is crop rotation?

A

Taking turns growing/harvesting different crops each year on the same land that take different quantities of mineral ions out of the soil

73
Q

Describe an example of crop rotation

A
  • Wheat has a high demand for nitrate ions

- Potatoes has a low demand of nitrate ions

74
Q

What percentage of our atmosphere is nitrogen?`

A

78%

75
Q

What does nitrogen-fixing bacteria do?

A

They convert nitrogen to nitrates

76
Q

What does denitrifying bacteria do?

A

Converts nitrates back into nitrogen

77
Q

What is waterlogged soil?

A

All internal spaces are concentrated with water (no air)

78
Q

How can you treat waterlogged soil?

A

Use a drainage system to unclog using pipes

79
Q

What does nitrifying bacteria do?

A

Converts ammonia into nitrates

80
Q

What is aerboic bacteria?

A

Bacteria that needs oxygen

81
Q

How does the nitrogen cycle?

A
  • Decomposers break down dead plants and animals and their waste products
  • Soil bacteria convert proteins and urea into ammonia
  • Nitrifying bacteria convert ammonia into nitrates
  • Plants absorb them from the soil and use it to make their proteins which are essential for growth
  • Plants eaten by herbivores and so the nitrogen gets passed along the food chain/web
  • Denitrifying bacteria live in waterlogged soils and convert nitrates back into nitrogen gas (menace to farmer)
  • Farmer may grow legumes to improve nitrogen content of soil or nitrogen fertiliser
  • Lightning can provide energy to convert nitrogen gas into nitrates
82
Q

How does growing legumes in a crop rotation improve the nitrogen content of soil?

A

These plants have swellings in their roots called nodules which contain nitrogen fixing bacteria which can convert nitrogen gas directly into nitrates

83
Q

Why is it best not to apply nitrogen fertiliser before it rains or too much?

A

It may cause eutrophication by spilling into the nearest river/stream

84
Q

What process makes synthetic fertiliser?

A

Haber Process

85
Q

Describe the substance trade between the roots of a legume and the leaves

A
  • Rhizobium (nodules) at end of plant root absorb nitrates and give to rest of plant
  • Leaves that capture glucose transfer to rhizobium
86
Q

What % of our bodies are composed of nitrogen compounds?

A

3%

87
Q

What is manure?

A

Animal waste used as fertiliser

88
Q

What does manure do?

A

Makes use of the decay process as fertiliser

89
Q

Why is the carbon cycle important?

A

carbon makes up the foundation of all organic material

90
Q

How much CO2 is in our air?

A

0.035%

91
Q

What is decomposition?

A

Respiration carried out by bacteria

92
Q

Describe the carbon cycle

A
  • Carbon taken from the atmosphere by plants by photosynthesis
  • Passed on to animals and decomposers by feeding
  • Returned to the air by respiration, burning fossil fuels and decomposition by microorganisms
93
Q

Is the water cycle an open or closed ciycle?

A

Closed

94
Q

Is there an energy input for the water cycle?

A

None apart from for evaporation

95
Q

Describe the water cycle

A
  • Water evaporates from oceans, lakes and rivers as water vapour
  • As air rises, it cools and condenses to form clouds
  • As water droplets get too large and heavy they fall as rain/snow
  • Groundwater moves through soil and rock to nearby rivers
  • Rivers flow into lakes and eventually returns to the ocean
96
Q

What is the cell cytoplasm mostly made of?

A

Water

97
Q

What is potable water?

A

Safe for drinking

98
Q

In places of drought, how can water be collected?

A

Catching droplets of water or misty air with collection pipes and cold nets for condensation

99
Q

What is desalination?

A

Obtaining fresh water from the sea/salty water