B7 Flashcards

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1
Q

What are the different levels of organisation in an ecosystem from individual organisms to the whole ecosystem?

A

There are 4 levels of ecological organisation. It starts at the lowest level: individual organisms, then populations, then communities, then finally to the whole ecosystem. Individual species of living organisms include every single plant and animal species that can be found on our planet

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2
Q

What is the importance of interdependence and competition in a community?

A

All organisms in an ecosystem depend upon each other. If the population of one organism rises or falls, then this can affect the rest of the ecosystem. If the foxes in the food chain above were killed, the population of rabbits would increase because they are no longer prey to the foxes.

To survive and reproduce, organisms require a supply of materials from their surroundings and from the other living organisms there.

Plants in a community or habitat often compete with each other for light and space, and for water and mineral ions from the soil.
Animals often compete with each other for food, mates and territory.

Within a community each species depends on other species for food, shelter, pollination, seed dispersal etc. If one species is removed it can affect the whole community. This is called interdependence. A stable community is one where all the species and environmental factors are in balance so that population sizes remain fairly constant.

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3
Q

What is an eco-system?

A

An ecosystem is the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment

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4
Q

Suggest the factors for which organisms are competing in a given habitat

A

To survive and reproduce, organisms require a supply of materials from their surroundings and from the other living organisms there.

Plants in a community or habitat often compete with each other for light and space, and for water and mineral ions from the soil.
Animals often compete with each other for food, mates and territory

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5
Q

Suggest how organisms are adapted to the conditions in which they live

A

Animals adapt in three different types of ways:

  • Behavioural
  • Physiological
  • Structural
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6
Q

What is a behavioural response?

A

Responses made by an organism that help it to survive/reproduce

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7
Q

What is a physiological response?

A

A body process that helps an organism to survive/reproduce

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8
Q

What is a structural response?

A

A feature of an organism’s body that helps it to survive/reproduce

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9
Q

Note:

A

AQA says that students should be able to extract and interpret information from charts, graphs and tables relating to the interaction of organisms within a community.

(Check page 83 on CGP)

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10
Q

What are the abiotic (non-living) factors which can affect a community?

A
  • Light intensity
  • Temperature
  • Moisture levels
  • Soil pH and mineral content
  • Wind intensity and direction
  • Carbon dioxide levels for plants
  • Oxygen levels for aquatic animals
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11
Q

How does a change in an abiotic factor would affect a given community given appropriate data or context?

A
  • Abiotic factors can have a significant impact on the food chain in an ecosystem
  • For example, changes in temperature or water levels can alter the populations of certain species, which can in turn affect the species that depend on them for it
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12
Q

Note:

A

AQA says that students should be able to extract and interpret information from charts, graphs and tables relating to the effect of abiotic factors on organisms within a community

(Check CGP page 84)

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13
Q

What are the biotic (living) factors which can affect a community

A
  • Availability of food
  • New predators arriving
  • New pathogens
  • One species outcompeting another so the numbers are no longer sufficient to breed.
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14
Q

How does a change in a biotic factor might affect a given community?

A

The abundance and distribution of organisms in an ecosystem are affected by biotic factors, which involve living organisms. the arrival of new predators : in balanced ecosystems, predators and prey have evolved together. the arrival of a new predator will disrupt numbers of prey and other organisms.

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15
Q

Note:

A

AQA says thats students should be able to extract and interpret information from charts, graphs and tables relating to the effect of biotic factors on organisms within a community

(Check page 84)

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16
Q

How organisms are adapted to live in their natural environment,given appropriate information

A
  • Organisms have features (adaptations) that enable them to survive in the conditions in which they normally live
  • These adaptations may be structural, behavioural or functional
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17
Q

What are organisms called if they live in environments that are extreme?

A
  • Some organisms live in environments that are very extreme, such as at high temperature, pressure, or salt concentration
  • These organisms are called extremophiles
  • Bacteria living in deep sea vents are extremophiles
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18
Q

What are photosynthetic organisms?

A

The producers of biomass for life on Earth

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19
Q

How are feeding relationships within a community represented by?

A
  • Feeding relationships within a community can be represented by food chains
  • All food chains begin with a producer which synthesises molecules
  • This is usually a green plant or alga which makes glucose by photosynthesis
20
Q

What do ecologists use to determine the distribution and abundance of species in an ecosystem?

A

A range of experimental methods using transects and quadrats

21
Q

Note:

A

In relation to abundance of organisms students should be able to:
• understand the terms mean, mode and median
• calculate arithmetic means
• plot and draw appropriate graphs selecting appropriate scales for the axes.

(Check page 87)

22
Q

State the food chain cycle

A
  • Producer: food chains always begin with a producer.
  • Primary consumer: producers are eaten by primary consumers (herbivores/omnivores)
  • Secondary consumer: primary consumers are eaten by secondary consumers (carnivores/omnivores)
  • Tertiary consumer: secondary consumers are eaten by tertiary consumers (carnivores/omnivores)
  • Producers are eaten by primary consumers, which in turn may be eaten by secondary consumers and then tertiary consumers.
23
Q

What are consumers that eat and kill other animals called?

A

Predators

24
Q

What are consumers that gets killed and eaten by other animals called?

A

Prey

25
Q

What is in a stable community?

A

In a stable community the numbers of predators and prey rise and fall in cycles

26
Q

Note:

A

AQA says that students should be able to interpret graphs used to model these food cycles.

(Check page 86 and online)

27
Q

Practical 7:

A
28
Q

What do many different materials cycle through?

A
  • The abiotic and biotic components of an ecosystem
  • All materials in the living world are recycled to provide the building blocks for future organisms
29
Q

Explain the importance of the carbon cycle for living organisms

A
  • The carbon cycle returns carbon from organisms to the atmosphere
  • As carbon dioxide to be used by plants in photosynthesis
30
Q

Explain the importance of the water cycle for living organisms

A
  • The water cycle provides fresh water for plants and animals on land before draining into the seas
  • Water is continuously evaporated and precipitated
31
Q

Explain the role of microorganisms in cycling materials through an ecosystem

A

By returning carbon to the atmosphere as carbon dioxide and mineral ions to the soil

32
Q

What is biodiversity?

A

Biodiversity is the variety of all the different species of organisms on earth, or within an ecosystem

33
Q

What does a great biodiversity ensure?

A

A great biodiversity ensures the stability of ecosystems by reducing the dependence of one species on another for food, shelter and the maintenance of the physical environment

34
Q

What does the future of the human species on Earth rely on?

A
  • The future of the human species on Earth relies on us maintaining a good level of biodiversity
  • Many human activities are reducing biodiversity and only recently have measures been taken to try to stop this reduction
35
Q

What does the rapid growth in the human population and an increase in the standard of living mean?

A
  • That increasingly more resources are used and more waste is produced
  • Unless waste and chemical materials are properly handled, more pollution will be caused
36
Q

How can pollution occur?

A

Pollution can occur:
* In water, from sewage, fertiliser or toxic chemicals
* In air, from smoke and acidic gases
* On land, from landfill and from toxic chemicals

37
Q

What does pollution do to animals?

A

Pollution kills plants and animals which can reduce biodiversity

38
Q

What is pollution?

A

Pollution is the introduction of harmful or poisonous substances into an environment

39
Q

How do human reduce the amount of land available for other animals and plants?

A

By building, quarrying, farming and dumping waste

40
Q

What does the destruction of peat bogs and other areas of peat to produce garden compost lead to?

A

Reduces the area of this habitat and thus the variety of different plant, animal and microorganism species that live between there (biodiversity)

41
Q

What does the decay or burning of the peat release?

A

Carbon dioxide into the atmosphere

42
Q

What has large-scale deforestation in tropical occued from?

A

Large-scale deforestation in tropical areas has occurred to:

  • Provide land for cattle and rice fields
  • Grow crops for biofuels
43
Q

What are some of the biological consequences of global warming?

A
  • Changes in or loss of habitats due to these extreme weather events
  • Decreases in biodiversity as food chains are disrupted and extinction rates increase
  • Increases in migration of species to new places, including increased spread of pests and disease.
44
Q

What contributes to global warming?

A

Levels of carbon dioxide and methane in the atmosphere are increasing, and contribute to ‘global warming’

45
Q

State positive human interactions in an ecosystem and their impact on biodiversity

A
  • Conservation - trying to keep hold of all the natural resources that we have on the planet before it becomes extinct.
  • Use of fertilisers to grow more products for human consumption
  • Introduce non-indigenous species to kill off pests, so that more products can be be produced without being ruined.
  • Breeding programmes for endangered species
  • protection and regeneration of rare habitats
  • reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
  • reduction of deforestation and carbon dioxide emissions by some governments
  • Encouraging the recycling of resources rather than dumping waste in land falls
46
Q

State negative human interactions in an ecosystem and their impact on biodiversity

A

Overuse of fertilisers - Fertilisers include nitrates, and it may run from fields into the river when it rains. This causes algae to grow, and it blocks out light from the plants that want to photosynthesize. Bacteria will now break down the plants and use up the oxygen which animals will need in the water.

Fish farming - Farming fish in a large area within the lake or sea is an issue as farmers will empty chemicals, waste, pathogens, and parasites into surrounding water. This reduces biodiversity as it harms other animals living nearby. Some fish will be fed on other wild fish, and the population of the wild fish will decrease. Some fish may escape and compete with the original fish that are found in the area. They will end up competing for the same food and habitat, therefore there will be less biodiversity. Some other fish may get trapped in the nets, and will die as a result of that.

New indigenous species that are introduced to kill pests may out-compete the natural species.

47
Q

What have scientists and concerned citizens put in place for ecosystems and biodiversity?

A

Scientists and concerned citizens have put in place programmes to reduce the negative effects of humans on ecosystems and biodiversity,These include:

  • Breeding programmes for endangered species
  • Protection and regeneration of rare habitats
  • Reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
  • Reduction of deforestation and carbon dioxide emissions by some governments
  • Recycling resources rather than dumping waste in landfill