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biology > topic 7:ecology > Flashcards

topic 7:ecology Flashcards

1
Q

State the levels of organisation in an ecosystem

A

Individual, population, community, ecosystem

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2
Q

What is an ecosystem?

A

The interaction between the living components and nonliving components

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3
Q

State the factors that plants may compete for

A

light
Space
Water
Mineral ions from soil

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4
Q

State the factors that animals might compete for

A

Food
Mates
Territory

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5
Q

what is intraspecific competition?

A

Competition within a species

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6
Q

What is interdependence?

A

different species in an ecosystem depend on each other for various resources, if one species is removed, the whole community may be affected 

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7
Q

What is a stable community?

A

A community in which all the biotic factors and all abiotic factors are balanced so that population sizes remain relatively constant

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8
Q

What are abiotic factors?

A

Nonliving factors

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9
Q

State the abiotic factors that may affect ecosystem

A

light intensity
Temperature
Moisture
Soil pH and mineral content
Wind intensity and direction
Carbon dioxide level
Oxygen level

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10
Q

why might light intensity affect ecosystem?

A

Different species of plants may have different optimum light intensity for growth

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11
Q

why does temperature affect an ecosystem?

A

Different species of plants and animals may have different optimum temperatures for growth and survival

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12
Q

How does soil pH affect an ecosystem?

A

certain plants may grow better in either alkaline or acidic soil

Soil pH may affect the appearance of the plant e.g. colour of hydrangea

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13
Q

How does moisture level affect an ecosystem?

A

many plants cannot survive in waterlogged soil as their roots cannot respire

Certain plants are adapted to high moisture levels

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14
Q

How does wind intensity affect an ecosystem?

A

Plant seeds are more likely to germinate in locations with lower wind intensity, which may also attract animals that depend on plant to live nearby

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15
Q

how does soil mineral content affect an ecosystem?

A

Most plants require a high level of soil minerals to grow well

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16
Q

Give an example of a type of plants that have adapted to low soil mineral content

A

Carnivores plants catch insects to compensate for the low level of soil mineral content

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17
Q

How does carbon dioxide concentration affect an ecosystem?

A

Higher carbon dioxide concentration leads to more plant growth

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18
Q

How does oxygen concentration affect an ecosystem?

A

Aquatic animals cannot survive in areas with low oxygen concentration

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19
Q

State the biotic factors that may affect an ecosystem

A

food
New predators
New pathogens
Competition

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20
Q

What are adaptations?

A

Features that enable organisms to survive in their living environment

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21
Q

what are organisms living in extreme environments called?

A

extremophiles

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22
Q

give free examples of extreme living environment

A

High temperature
High pressure
High salt concentration

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23
Q

State an example of where extremophile bacteria can be found

A

in deep sea vents

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24
Q

Define population

A

A species that occupy the same habitat

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25
Q

Define habitat

A

The place in which an organism lives

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26
Q

define community

A

Populations of different species interacting

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27
Q

Define ecosystem

A

The interactions between their biotic and abiotic factors in an area

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28
Q

what do food chain show?

A

Food chain show the feeding relationships of different organisms and the flow of energy between the organisms

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29
Q

Define biomass

A

The total mass of living material

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30
Q

what are trophic levels

A

The stages in a food chain

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31
Q

What do arrows in a food chain represent?

A

The direction of biomass transfer 

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32
Q

Describe a simple food chain

A

produce—-> primary consumer——> secondary consumer—-> tertiary consumer

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33
Q

What is a producer?

A

An organism that makes its own food

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34
Q

what type of organisms are primary producers

A

Photosynthetic organisms like green plants and algae that trap energy from the Sun

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35
Q

what is a primary consumer?

A

An organism that feeds on producers

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36
Q

What is a secondary consumer?

A

An organism that feeds on primary consumers

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37
Q

what is a tertiary consumer?

A

An organism that feeds on secondary consumers

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38
Q

What is a predator?

A

A consumer that kills and eat other animals

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39
Q

What is pray?

A

An animal that is killed and eaten by another animal

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40
Q

Describe the pattern of predators and pray in a stable community

A

The numbers of predators and pray rise and fall cycles

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41
Q

Why are producers the first trophic level?

A

produces provide all biomass for the food chain

The rest of the food chain involves the transfer of this bio mass

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42
Q

what piece of apparatus is used to measure the abundance and distribution of organisms in an area?

A

Quadrat

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43
Q

what piece of operators is used to study the distribution of organisms across a gradient?

A

belt transect 

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44
Q

When considering the abundance of organisms, what is meant by the term mean?

A

The average number of organisms

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45
Q

how is the arithmetic mean calculated?

A

some of each number of each organism

Divide

The total number of each type of organism

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46
Q

When considering their abundance of different organisms, what is meant by the term mode?

A

The most populous organism

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47
Q

when considering the abundance of organisms, what is meant by the term median?

A

The organism that represents the middle value when the numbers of each organism are arranged from lowest to highest

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48
Q

describe how material cycle through the living and nonliving components of an ecosystem

A

Organisms take in elements from their surroundings, e.g. soils, air

Elements converted to complex molecules which become biomass

Elements transferred along food chain

Elements returned to the environment during excretion and decomposition of dead organisms

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49
Q

Give three molecules which are cycled for ecosystem

A

Oxygen, carbon dioxide and water

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50
Q

Describe the carbon cycle

A

plants fix carbon dioxide into organic molecules during photosynthesis

The organic carbon containing molecules are passed onto organisms that eat the plants

Carbon Dioxide is released back into the atmosphere by respiration from animals and plants

Burning fossil fuels also releases carbon dioxide into the atmosphere

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51
Q

why is the carbon cycle important?

A

Carbon contain molecules such as glucose are important for living organisms to grow and provide energy for vital functions within cells

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52
Q

Describe the water cycle

A

water from Lakes and oceans evaporates

The evaporated water condenses into clouds and returns to earth as precipitation

The water from precipitation is used for life on land

The water then returns to rivers and oceans through surface run-off

53
Q

why is the water cycling important?

A

Living organisms require water and the water cycle provides organisms on land with a continuous supply of water

54
Q

Why are micro organisms important for the cycling of materials through an ecosystem?

A

microorganisms return carbon to the environment by releasing carbon dioxide through respiration while they decompose dead matter. The decomposition of dead matter in soil returns minerals to the environment for other organisms to use e.g. plants use mineral irons for growth.

55
Q

What is meant by decomposition?

A

The breakdown of dead materials into simpler organic matter

56
Q

How to decompose breakdown dead matter

A

Decomposers where these enzymes which catalyse the breakdown of dead material into smaller molecules

57
Q

what are the two types of decomposition?

A

Aerobic decomposition with oxygen

Anaerobic decomposition without oxygen

58
Q

What factors affect the rate of decomposition?

A

oxygen availability

Temperature

Water content

59
Q

why is oxygen required for decomposition?

A

Most decomposers require oxygen for aerobic respiration

60
Q

How does the availability of oxygen affect the rate of decomposition?

A

as oxygen levels increase, the rate of decomposition increases

As oxygen levels decrease the rate of decomposition decreases

61
Q

Why can decomposition still occur in the absence of oxygen?

A

some decomposers respire anaerobically

However, the rate of decomposition is slower as anaerobic respiration produces less energy

62
Q

How does soil water content affect the rate of decomposition?

A

decomposers require water to survive

in moist conditions the rate of decomposition is high

In waterlogged soils, there is little oxygen for respiration so the rate of decomposition decreases

63
Q

why does decomposition require water?

A

Water is required for the secretion of enzymes and absorption of dissolved molecules

64
Q

How does temperature affect the rate of decomposition?

A

decomposers release enzymes

Rate highest at 50 Celsius

Lower temperature, enzymes work too slow slowly, rate decreases

Higher temperatures, enzymes denature, decomposition stops

65
Q

how is the rate of change calculated when considering the decay of biological material?

A

Rate of change= change in value
————————
Change in time

where value is a measurable variable associated with the decay of the material

66
Q

what is compost

A

The nutrient rich product of the rapid decay of waste biological material(dead plants and animal waste) iin optimum condition set by gardeners and farmers

67
Q

How is compost used?

A

Use is a natural fertiliser to promote growth of crops or garden plants

68
Q

Describe how biogas generators work

A

Bio gas generators provide methane gas for fuel through anaerobic decomposition that occur in animal waste

69
Q

Describe how environmental conditions affect communities

A

environmental conditions, e.g. temperature, soil pH, light intensity affect the abundance and distribution of organisms within communities

E.g. rising global temperatures that have been linked to extension of frog species(their thin skin makes them more vulnerable to temperature changes)

70
Q

how can different temperatures be bad for certain communities?

A

If the temperature is too low, growth will be slower as organisms will use more energy to stay warm

If the temperature is too high organisms can die and water will become limited as evaporation increases

71
Q

How can changes in water levels affect ecosystems?

A

animals may have to migrate to find water

Melting ice caps may destroy the habitats of some animals

72
Q

How can atmospheric gases affect ecosystems?

A

some organisms cannot survive when certain gases are present

Polluted water can cause illness to animals that drink it

73
Q

What detrimental impacts can sulphur dioxide have on the environment?

A

formed when fossil fuels containing impurities are burnt

Sulphur dioxide can dissolve in water to form acid rain which can road buildings and pollute water sources

74
Q

What detrimental impacts can carbon monoxide have on environment?

A

carbon monoxide is formed from the incomplete combustion of fossil fuels

Carbon monoxide binds irreversible to haemoglobin which prevent it from carrying oxygen

Too much pressure can cause unconsciousness and death

75
Q

Name five greenhouse gases

A

water vapour
Carbon dioxide
Nitrous oxide
Methane
CFCs

76
Q

A 3 human activities that contribute to greenhouse gases

A

Burning fossil fuels
Deforestation
Large scale livestock farming

77
Q

how do greenhouse gases lead to global warming?

A

Greenhouse gases allow heat from the Sun to enter the atmosphere

The gas gases act as a blanket and trap the heat in the atmosphere

78
Q

State three negative consequences of global warming

A

Sea level rise caused by melting icebergs

Distributed farming and agriculture

Increase spread of diseases in warmer climates

79
Q

What is biodiversity?

A

Variety of the different species on earth or within an ecosystem

80
Q

What is the importance of biodiversity?

A

To maintain the stability of an ecosystem

81
Q

how does biodiversity ensure the stability of an ecosystem?

A

It reduces the dependent on particular species for resources, e.g. food and shelter to that even if one species is removed over species can still survive

82
Q

why have humans consumption of resources and waste production increased?

A

Rapid rising human population

Increase in standard of living

83
Q

Where does pollution occur?

A

Air, land, water

84
Q

State an example of water pollutants

A

Sewage, fertiliser, chemicals

85
Q

how does eutrophication occur?

A

Fertiliser from farms pollute the water, causing excessive algae, depleting the oxygen in the water, causing other plants and animals to die

Dead plants are decomposed by bacteria and the oxygen levels decrease further

86
Q

State an example of air pollutants

A

Smoke
Acidic gases

87
Q

State an example of land pollutant

A

Landfill waste, chemicals

88
Q

Which human activities reduce the land available for animals and plants?

A

building, farming, quarrying, disposing of waste

89
Q

why have Peat bogs been destroyed?

A

To produce compost to increase food production

90
Q

why does the destruction of peatBoggs greatly contribute to the greenhouse effect?

A

peat bogs are stores of carbon and burning their releases a large volume of carbon dioxide into the atmosphere

91
Q

why have large scale deforestation activities occurred?

A

To provide land for cattle or Ricefield

To grow crops to produce biofuels

92
Q

what is the greenhouse effect?

A

Greenhouse gases trapped energy from the Sun as heat in the atmosphere keeping the temperature on Earth suitable for life

93
Q

What is causing global warming?

A

The increase in levels of greenhouse gases, e.g. carbon dioxide in methane, causing the temperature on Earth to increase

94
Q

What are the harmful effects of deforestation?

A

destruction of many animal habitats

Releases large amounts of greenhouse gases

95
Q

State the consequences of global warming

A

Rising sea levels
Melting polar ice caps
Changing weather patterns
Migration of animals to find suitable habitats
Tropical diseases becoming more common
Extinction of species

96
Q

Describe the steps taken to maintain biodiversity

A

breeding programs for endangered species

Protection and rebuilding habitats

replanting field margins and hedgerows

Reduce deforestation

Reduce carbon dioxide emissions

Recycling rather than disposing in landfills

97
Q

What is the purpose of replanting hedgerows and field margins?

A

There is a higher by diversity in the margins than the fields that they surround

98
Q

what does a food chain show?

A

It describes a feeding relationship between organisms and the resultant stages of biomass transfer

99
Q

what are trophic levels

A

The stages in a food chain

100
Q

how are trophic levels represented?

A

Trophic levels are represented by number numbers, starting from one. After one, trophic levels are numbered according to far along the organism is in the food chain.

101
Q

what is trophic level one?

A

Plants and algae which make their own food through photosynthesis – called producers

102
Q

what is trophic level two?

A

Herbivores which eat producers – called primary consumers

103
Q

what is trophic level three?

A

Carnivores that eat herbivores – called secondary consumers

104
Q

What is trophic level four?

A

Carnivores that eat other carnivores – called tertiary consumers

105
Q

what is an Apex predator?

A

A carnivore with no predators

106
Q

How do composers breakdown dead matter?

A

Decomposers releases enzymes which catalyse the breakdown of dead material in smaller icicles. So both small food molecules then diffuse into microorganisms.

107
Q

what is biomass

A

The dry mass of all living organisms in an area

108
Q

Why is dry mass used for biomass 

A

Because the wet mass varies as the volume of water in the organism varies

109
Q

what percentage of the incident energy from light for photosynthesis do producers transfer

A

1 percent

110
Q

What percentage of the biomass from one trophic level is transferred to the level above it in feeding

A

Approximately 10%

111
Q

Why are buyer mass transfer is not 100% efficient?

A

Energy is lost through

egestion
Excretion
Respiration in which large amounts of glucose are used
The production of inedible bones and shell

112
Q

how does the efficiency of biomass transfers affect the number of trophic levels in a biomass pyramid?

A

The less efficient the transfers, the fewer trophic levels are the few organisms in higher trophic levels

113
Q

What is a biomass pyramid?

A

A pyramid that shows the total dry mass of organisms at each trophic level

Trophic level one is at the bottom of the pyramid

114
Q

What is a pyramid of numbers?

A

A pyramid of number shows the number of organisms at each trophic level

115
Q

Identify the producer in this pyramid of biomass

A

D is the producer

116
Q

why is this pyramid of numbers not pyramid shaped?

A

Pyramids of numbers don’t take size and mass of organisms into account

117
Q

what is food security?

A

having enough food to be able to feed a population

118
Q

State the biological factors of threatening food security

A

rising birth rates
Changing diets in developed countries – food is transported around the world
New pests and pathogens
environmental changes affecting food production
Increase cost of agriculture
Armed conflicts

119
Q

How does intensive farming increase the production of animals?

A

Feed animals high protein foods to increase growth

Reduce the energy loss to the environment:
-Limiting movement
-Regulating their surrounding temperature

Feed animals, antibiotics to prevent diseases

120
Q

What are the advantages of intense farming?

A

 high yield of food
More efficient
Allows easier quality control

121
Q

what are the disadvantages of intense farming?

A

May lead to antibiotic resistance
Cost is high
Ethical objections, e.g. limiting movement of animals may cause them harm
Biodiversity may be reduced

122
Q

how can fish stocks be conserved?

A

Control the size of gaps in fishing nets to prevent juvenile fish from being killed. Before reaching reproductive maturity.

Introduced fishing quotas

123
Q

what is a transgenic organism

A

an organism that has been genetically modified to contain genetic material from another source

124
Q

Stay an example of genetically modified foods

A

Golden rice

125
Q

how might crops be genetically modified?

A

to improve nutritional value
To be pest resistance
To be pesticide resistant

126
Q

what are the advantages of golden rice

A

 it contains additional beta- carotene which can be converted to vitamin A in the body, supplementing people who do not obtain enough vitamin A in their diet to prevent Nightblindness from farming 

127
Q

what is mycoprotein?

A

A protein rich substance used to make meat substitute food for vegetarians and vegans

128
Q

how is mycoprotein produced

A

fusarium-a fungus, is grown on glucose syrup, in aerobic conditions and the biomass is harvested and purified to get the mycoprotein

biology (10 decks)

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