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OCR A level biology > Biodiversity > Flashcards

Biodiversity Flashcards

1
Q

Define abiotic factors

A

Non-living conditions in a habitat

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2
Q

Define belt transect

A

Two parallel lines are marked along the ground and samples are taken out of the area at specified points

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3
Q

Define biodiversity

A

The variety of living organisms present in an area

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4
Q

Define species

A

The smallest and most specific taxonomic group

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5
Q

Define Succession

A

The progressive replacement of one dominant type of species or community by another in an ecosystem, until a stable climax community is established.

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6
Q

Define intraspecific variation

A

The differences between organisms of the same species

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7
Q

Define interspecific varation

A

The difference between organisms of different species

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8
Q

Define monoculture

A

The cultivation of a single crop in a given area

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9
Q

Define normal distribution curve

A

The bell-shaped curve that results from plotting continuous variation data on a graph

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10
Q

Define correlation coefficient

A

Statistical test used to consider the relationship between two sets of data

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11
Q

Define keystone species

A

Species which are essential for maintaining biodiversity-they have a disproportionately large effect on their environment relative to their abundance

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12
Q

Define stratified sampling strategy

A

Populations are divided into strata based on a particular characteristic
A random sample is then taken from each of the strata proportional to its size

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13
Q

Define random sampling

A

Sampling where each individual in the population has an equal likelihood of selection

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14
Q

Define kingdom

A

The second biggest and broadest taxonomic group

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15
Q

Define autotrophic

A

Organisms that acquire nutrients by photosynthesis

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16
Q

Define genetic bottleneck

A

When large numbers of a population die prior to reproducing leading to reduced genetic biodiversity within the population

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17
Q

Define mutation

A

A change in the genetic material of an organism which may affect the phenotype of an organism

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18
Q

Define community

A

All populations of living organisms in a particular habitat

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19
Q

What is the founder effect?

A

When a few individuals of a species colonise a new area, their offspring initially experience a loss in genetic variation and rare alleles become much more common within the population

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20
Q

Define discontinuous variation

A

A characteristic that can only result in certain discrete values

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21
Q

Give an example of discontinuous variation

A

Blood type

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22
Q

Define continuous variation

A

A characteristic that can take any value within a range

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23
Q

Give an example of continuous variation

A

Height

Weight

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24
Q

Define divergent evolution

A

Species diverge over time into two different species, resulting in a new species becoming less like the original one

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25
Q

What is ex situ conversation?

A

Conservation methods out of the natural habitat

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26
Q

What is a seed bank?

A

A store of genetic material from plants in the form of seeds

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27
Q

Define gene flow

A

When alleles are transferred from one population to another by interbreeding

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28
Q

Define natural selection

A

The process by which organisms best suited to their environment survive and reproduce, passing on their characteristics to their offspring via their genes

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29
Q

Define ecosystem

A

All the interacting living organisms and non-living conditions in an area

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30
Q

Define habitat

A

The natural environment of an organism

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31
Q

Define population

A

The number of organisms of the same species living in a particular geographic area

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32
Q

What are the 3 types of biodiversity?

A
  • habitat
  • species
  • genetic
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33
Q

What is habitat biodiversity?

A

The number of different habitats

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34
Q

What is species biodiversity?

A

The number of species and the abundance of each species in a particular location

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35
Q

What is genetic biodiversity?

A

The total number of genetic characteristics in the genetic make-up of a species

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36
Q

What is sampling?

A

The process of collecting data in a suitable way

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37
Q

Why is sampling important?

A
  • means data is representative is as it can be

- makes data collection more manageable

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38
Q

What is random sampling?

A

Each individual in the population has an equal likelihood of selection

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39
Q

What is non-random sampling?

A

An alternative sampling method where the sample is not chosen at random

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40
Q

How could an area be randomly sampled?

A
  • a grid could be laid out using two tape measures
  • a random number generator is used to generate a grid reference
  • a quadrat is placed at the grid reference
  • a sample is collected
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41
Q

What are the 3 main non-random sampling techniques?

A
  • opportunistic (pragmatic)
  • stratified
  • systematic
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42
Q

What is opportunistic sampling?

A

Sampling which uses organisms conveniently avaliable

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43
Q

What is stratified sampling?

A
  • some populations can be divided into distinct groups

- a random sample is then taken from each of these groups proportional to its size

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44
Q

What is systematic sampling?

A

Samples are taken at regular intervals

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45
Q

What is a frame quadrat?

A

A frame quadrat consists of a square frame divided into a grid of equal sections

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46
Q

What is a point quadrat?

A

a point quadrat consists of a frame containing a horizontal bar, pins can be pushed down at set intervals to reach the ground. The plant which the pin touches is what is recorded

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47
Q

What is a line transect?

A

A line is marked along the ground between two points and samples are taken at specified points

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48
Q

What is a belt transect?

A

Two parallel lines are marked and samples are taken of the area between the two lines

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49
Q

What is an interrupted belt transect?

A

A transect is marked out and frame quadrats are placed at regular intervals along the transect

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50
Q

When would systematic sampling be useful?

A

When studying how biodiversity changes along an area

51
Q

When would random sampling be useful?

A

If the study is only looking at biodiversity in one area

52
Q

Give 5 methods of sampling animals

A
  • using pooters
  • sweep nets
  • pitfall trap
  • tree beating
  • kick sampling
53
Q

What kind of animals are sampled using a pooter?

A

Small insects

54
Q

What kind of animals are sampled using sweep nets

A

Insects, particularly those that live in long grassland

55
Q

What kind of animals are sampled using pitfall traps?

A

Small crawling invertebrates

56
Q

What kind of animals are sampled using tree beating?

A

Invertebrates which live in trees/bushes

57
Q

What kind of animals are sampled using kick sampling?

A

Animals which inhabit river beds

58
Q

Describe how pooters can be used to sample animals

A

By sucking on a mouthpiece insects are drawn into the holding chamber

59
Q

Describe how pitfall traps can be used to sample animals

A
  • a hole is dug and insects fall in

- this is left overnight so nocturnal species are also sampled

60
Q

Why must a pitfall trap have a roof structure?

A

To prevent the hole filling with rainwater

61
Q

Describe how tree beating can be used to sample animals

A
  • a large white cloth is stretched out under the tree
  • the tree is then shaken/beaten
  • animals fall onto the sheet where they can be collected
62
Q

Describe how kick sampling can be used to sample animals

A
  • the riverbank and bed are kicked to disturb substrate

- a net is held downstream to capture organisms that have been disturbed

63
Q

Give the 2 ways plants can be sampled

A
  • frame quadrats

- point quadrats

64
Q

Define biotic factor

A

The living components of an ecosystem

65
Q

Give 3 ways frame quadrats can be used to sample plants

A

Frame quadrats can be used to generate data on:

  • density
  • % cover
  • frequency
66
Q

What is used to measure wind?

A

Anemometer

67
Q

What is used to measure Oxygen content in water

A

Dissolved O2 probe

68
Q

Why would a temperature probe linked to a data logger be advantageous over a thermometer?

A
  • rapid changes can be detected
  • human error in taking reading reduced
  • high degree of precision can be achieved
  • data can be stored and tracked on a computer
69
Q

What are the 2 ways of measuring biodiversity?

A
  • Species richness

- Species evenness

70
Q

What is species richness?

A

A measure of the number of different species living in an area

71
Q

What is species evenness?

A

How close in number the populations of each species in an environment are

72
Q

What information is required to determine species evenness?

A

Number of each species in an area

73
Q

What information is required to determine species richness?

A

Total number of species present

74
Q

How can population size of a plant population be estimated?

A

Through the use of frame quadrats to find density or frequency

75
Q

How can the size of an animal population be determined?

A

Mark-release-recapture

76
Q

Outline the process of mark-release-recapture

A
  • organisms are captured and marked with a non-toxic marking
  • time is allowed for organisms to redistribute
  • the organisms are recaptured and the number of marked animals is compared to the number of unmarked animals
77
Q

What is the relationship between diversity of an ecosystem and stability of the ecosystem?

A

Greater the species diversity, the greater the stability of an ecosystem (usually)

78
Q

What is the usual effect of pollution on biodiversity?

A

Pollution usually reduces biodiversity

79
Q

Why can low species diversity indicate pollution is present?

A

Pollution usually results in harsh conditions, so few species tend to dominate, and biodiversity is reduced

80
Q

What is Simpson’s index of diversity?

A

A measurement of biodiversity which takes into account both species richness and species evenness

81
Q

What is the range of values for Simpson’s biodiversity index?

A

Simpson’s biodiversity index always results in a value between 0 and 1

82
Q

What does a higher result of Simpson’s diversity index indicate?

A

A more diverse habitat. The higher the value of Simpson’s diversity index, the more diverse the habitat

83
Q

What are the features of an area with low biodiversity?

A
  • relatively few successful species
  • stressful and/or extreme conditions
  • few species live in habitat and those which do have very specific adaptations
  • relatively simple food webs
  • change to whole ecosystem has major effects
84
Q

What are the features of an area with high biodiversity?

A
  • a large number of successful species
  • relatively benign/not stressful conditions
  • many species live in the habitat
  • complex food webs
  • often relatively small effect on ecosystem if there is a change to ecosystem
85
Q

What is the effect of greater genetic biodiversity on the survival of a species?

A

Greater genetic biodiversity increase the change of the long term survival of a species

86
Q

Why does greater genetic biodiversity increase the chance of long term survival for a species?

A
  • better able to adapt to changes in their environment
  • there are likely to be some organisms within the population that carry an advantageous allele
  • which enables them to survive in the altered conditions
87
Q

How can genetic diversity of a population be increased?

A
  • mutations in DNA of an organism

- interbreeding between different populations (gene flow)

88
Q

How can genetic biodiversity of a population be decreased?

A
  • selective breeding
  • captive breeding
  • natural selection
  • genetic bottleneck
  • genetic drift
89
Q

How does deforestation reduce biodiversity?

A
  • reduces the number of animal species in an area as it destroys their habitat
  • food sources are reduced/removed
  • animals are forced to migrate to other areas
90
Q

Give 3 ways human have reduced biodiversity

A
  • deforestation
  • agriculture
  • climate change
91
Q

How does removal of hedgerows reduce biodiversity?

A
  • reduces number of plant species in an area
  • destroys habitat for animals
  • reduces/removes food sources
92
Q

Give 3 ways agriculture reduces biodiversity

A
  • removals of hedgerows
  • monoculture
  • use of pesticides and herbicides
93
Q

What is monoculture?

A

The farming technique where only one crop is grown

94
Q

What is global warming?

A

A gradual increase in overall temperature of the earth due to pollutants released and the greenhouse effect

95
Q

What is climate change?

A

A change in global or regional climate patterns due to increasing levels of CO2 in the atmosphere produced by use of fossil fuels

96
Q

Give 4 ways climate change will reduce biodiversity

A
  • rising sea levels flood low lying land
  • insect life cycles and population would change
  • saltwater would flow further up rivers
  • in some areas rainfall would lower
97
Q

What are the 3 categories of reasons for maintaining biodiversity?

A
  • ecological
  • aesthetic
  • economic
98
Q

Give an ecological reason why biodiversity should be maintained

A

-all organisms are interdependent on others for survival, removal of one species may have significant effect on others

99
Q

Give 2 aesthetic reasons why biodiversity should be maintained

A
  • natural world provides inspiration for people

- studies have shown that patients recover more quickly when supported by the natural environment

100
Q

Give 4 economic reasons why biodiversity should be maintained

A
  • species with potential economic importance may become extinct before they are discovered
  • continuous monoculture depletes soil of nutrients and so makes the ecosystem more fragile
  • greater biodiversity means greater potential for the manufacture of different products in the future
  • high biodiversity provides protection against abiotic stress factors and disease
101
Q

Define invasive species

A

An organism that is not native to an area and has negative effects on the economy, environment, or health

102
Q

Describe the role of marine conservation zones in maintaining biodiversity

A
  • vital in protecting species rich areas e.g. coral reefs
  • doesn’t prevent fisherman in the area
  • creates area of refuge within which populations can build and repopulate adjacent areas
103
Q

What is a downside of marine conservation zones?

A

Large areas are required

104
Q

How are seeds stored in a seed bank?

A

The seeds are dried and stored at -20 degrees

105
Q

Give 4 examples of active management of wildlife reserves

A
  • controlled grazing
  • restricting human access
  • controlling poaching
  • culling/removal of invasive species
106
Q

Give 2 examples of in situ conservation

A
  • marine nature reserves

- land nature reserves

107
Q

Give 3 examples of ex situ conservation

A
  • seed banks
  • botanic gardens
  • captive breeding programmes
108
Q

Why are seed banks used?

A
  • seeds stored so new plants may be grown in the future

- stores seeds for reintroduction and research for breeding and genetic engineering in the future

109
Q

Give a problem with seed banks

A

Not all seeds are still viable after being frozen

110
Q

What are captive breeding programmes?

A

Offspring of endangered species are bred in a human controlled environment

111
Q

How do captive breeding programmes try to maintain genetic diversity?

A
  • an international catalogue of individuals’ genealogical data is maintained
  • mating can be arranged to ensure genetic diversity is maximised
112
Q

Why might some captively bred organisms not be able to be released into the wild?

A
  • loss of resistance to local diseases
  • learned behaviour
  • genetic make-up of captive animals can become so different to original population they cannot interbreed
  • natural habitat must be restored before populations are introduced
113
Q

Give an advantage of in situ conservation

A

It enables a species to adapt continually to changing environmental conditions

114
Q

Give a disadvantage of ex situ conservation

A

It is very expensive, more expensive than in situ conservation

115
Q

What does IUCN stand for?

A

International union for conservation of nature

116
Q

What does the IUCN do?

A
  • assist in securing agreements between nations

- publishes the red list showing status of threatened animals

117
Q

What does CITES stand for?

A

Convention on international trade in endangered species

118
Q

What does CITES do?

A

-regulates international trade of wild plants and animals and their products

119
Q

What was the Rio convention?

A

A meeting between 172 nations about how to maintain biodiversity

120
Q

Give 2 examples of agreements the Rio convention resulted in

A
  • CBD

- UNCCD

121
Q

What does CBD stand for?

A

Convention on biological diversity

122
Q

What does UNCCD stand for?

A

United nations convention to combat desertification

123
Q

Give an example of a UK based conservation scheme

A

Countryside stewardship scheme

124
Q

Outline the countryside stewardship scheme

A
  • governmental payments offered to farmers to enhance and conserve the English landscape
  • restoring neglected land
  • local conservation schemes

OCR A level biology (44 decks)

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