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A-level Biology > 11 - Biodiversity 🪸 > Flashcards

11 - Biodiversity 🪸 Flashcards

1
Q

What is habitat biodiversity?

A

the number of different habitats found within an area

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2
Q

What is the habitat biodiversity in the UK?

A

Large, due to meadows, woodlands, streams and sand dunes

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3
Q

What is the habitat biodiversity in Antartica?

A

Smaller, as all covered by ice

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4
Q

What is the two components of species biodiversity?

A

species richness and species evenness

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5
Q

What is species richness?

A

the number of different species living in an area

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6
Q

What is species evenness?

A

the comparison of the number of individuals of each species living in a community

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7
Q

What is genetic biodiversity?

A

the variety of genes that make up a species

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8
Q

What does greater genetic biodiversity result in?

A

A species better adapted to their environment

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9
Q

Define sampling

A

taking measurements of a limited number of individual organisms present in an area

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10
Q

What is the number of individuals in a species known as?

A

the abundance

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11
Q

What can the results of a sample be used for?

A

To make generalizations, estimates on numbers, characteristics and species distribution

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12
Q

What is random sampling?

A

Selecting individuals by chance, so each individual in a population has an equal likelihood of selection

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13
Q

How can random sampling be done?

A

Using a computer to randomly generate coordinates

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14
Q

What are the 3 non-random sampling techniques?

A
  • Opportunistic
  • Stratified
  • Systematic
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15
Q

What is opportunistic sampling?

A

The weakest form of sampling because it uses organisms that are conveniently available

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16
Q

What is stratified sampling?

A

Dividing populations into a number of sub-groups, then randomly selecting individuals from those

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17
Q

What is systematic sampling?

A

Different areas within an overall habitat are identified, which are then sampled separately

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18
Q

What is a line transect?

A

Marking a line along the ground between 2 poles, and taking samples at specific points

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19
Q

What is a belt transect?

A

Two parallel lines are marked, and samples are taken of the area between the 2 lines

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20
Q

What impacts the reliability of sampling?

A
  • sampling bias
  • chance
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21
Q

Why is it important to conserve habitats with low biodiversity?

A

Rare species may not survive elsewhere

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22
Q

What does Simpson’s Index of Diversity measure?

A

biodiversity, taking it account both species richness and evenness

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23
Q

What does 0 mean in Simpson’s Index of Diversity?

A

no diversity

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24
Q

What does 1 mean in Simpson’s Index of Diversity?

A

infinite diversity

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25
Q

How is genetic biodiversity created amongst species?

A

Alleles

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26
Q

Increasing Genetic Biodiversity

What is gene flow?

A

When an individual migrates from one population and breeds with a member of another population - interbreeding

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27
Q

Decreasing Genetic Biodiversity

What is selective breeding?

A

Specific individuals are chosen to breed for their advantageous characteristics

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28
Q

Decreasing Genetic Biodiversity

How does captivity decrease genetic biodiversity?

A

Where only a small number of individuals of a species are available to breed

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29
Q

Decreasing Genetic Biodiversity

How does natural selection decrease this?

A

Species with advantageous characteristics live, and less advantageous characteristics are lost

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30
Q

Decreasing Genetic Biodiversity

What are genetic bottlenecks?

A

Where few individuals within a population survive an event or change

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31
Q

Decreasing Genetic Biodiversity

What is the founder effect?

A

Where a small number of individuals create a new colony, geographically isolated from the original. The gene pool for this new population is small

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32
Q

Decreasing Genetic Biodiversity

What is genetic drift?

A

Due to random nature of gene inheritance from parents, the frequency of occurrence of an allele will vary

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33
Q

What are polymorphic genes?

A

genes that have more than one allele

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34
Q

Are most genes polymorphic or monomorphic?

A

Monomorphic = a single allele exists for the gene

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35
Q

What is the advantage of monomorphic genes?

A

The basic structure of individuals within a species remains consistent

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36
Q

Formula for the proportion of polymorphic gene loci

A

number of polymorphic gene loci / total number of loci

37
Q

What does the greater proportion of polymorphic gene loci mean?

A

Greater genetic biodiversity

38
Q

What 3 bad humans influences are on biodiversity?

A
  • deforestation
  • agriculture
  • climate change
39
Q

How does deforestation affect biodiversity?

A
  • reduces number of trees
  • reduces species diversity
  • reduces habitats
  • forces migration
40
Q

How does agriculture affect biodiversity?

A
  • deforestation to create space
  • removal of hedgerows
  • use of chemicals
  • herbicides used to kill insects
  • monoculture
41
Q

How does climate change affect biodiversity?

A
  • melting of polar caps removes habitat
  • rising sea levels
  • higher temp and less rainfall changes environment
42
Q

Reasons for maintaining biodiversity

Why is it maintained for aesthetic reasons?

A
  • enriches our lives
  • nature provides inspiration
  • reduces stress
43
Q

Reasons for maintaining biodiversity

Why is it maintained for ecological reasons?

A
  • organisms are interdependent on each other for survival
  • keystone species maintain the structure of an ecology community
44
Q

What are keystone species?

A

Species that have a disproportionally large effect on their environment relative to their abundance

45
Q

Reasons for maintaining biodiversity

What economical reasons for maintaining biodiversity are there?

A
  • conserve natural resources
  • medicines
  • protection against natural disasters
  • ecotourism
46
Q

Reasons for maintaining biodiversity

What are the farming reasons for maintaining biodiversity?

A
  • prevents soil depletion, so crops have good yields
  • to prevent soil erosion and desertification affecting yield
47
Q

Reasons for maintaining biodiversity

What are the farming reasons for maintaining biodiversity?

A
  • prevents soil depletaion, so crops have good yeilds
48
Q

Define conservation

A

the preservation and careful management of the environment

49
Q

What is in situ conservation?

A

within the natural habitat

50
Q

What is ex situ conservation?

A

outside of the natural habitat

51
Q

What are the categories of conservation statuses?

A
  • extinct
  • extinct in the wild
  • endangered
  • vulnerable
  • non-threatened
  • least concern
52
Q

Define sustainable development

A

economic development meeting today’s needs without impacting the future

53
Q

Pros of in situ conservation

A
  • maintains genetic biodiversity
  • allows evolution so the species can continuously adapt to the environment
  • preserves interdependent relationships
  • cheaper
54
Q

In situ

What is necessary for successful wildlife reserves?

A

active management

55
Q

In situ

What are some active management techniques in wildlife reserves?

A
  • controlled grazing
  • restricting human access
  • controlling poaching
  • feeding animals
  • reintroduction of species
  • removing invasive speeches
  • halting succession
56
Q

What is succession?

A

a natural process in which early colonizing species are replaced over time until a stable mature population is achieved

57
Q

In situ

What is the only statutory marine reserve in England?

A

Lundy Island

58
Q

In situ

Why are marine reserves so important?

A

to preserve species-rich areas

59
Q

When is ex situ conservation normally used?

A

Alongside in situ

60
Q

Ex situ

How can botanic gardens help to maintain biodiversity?

A

Plant species can be provided with the best resources to grow

61
Q

Ex situ

How do seed banks maintain biodiversity?

A

store seeds so new plants can grow in the future

62
Q

Ex situ

Why can’t all plant seeds be stored in seed banks?

A

some seeds die when dried and frozen (most tropical rainforest tree seeds)

63
Q

Ex situ

What do captive breeding programs do?

A

Create a stable, healthy population of a species, and then reintroduce them into their natural environment

64
Q

Ex situ

Why is maintaining genetic diversity in captive breeding programs hard?

A

All bred together, so inbreeding

65
Q

Ex situ

Why might some organisms born in captivity not then be suitable for release into the wild?

A
  • disease
  • behavior
  • genetic races
  • habitat
66
Q

Conservation Agreements

What do the International Union for the Conservation of Nature do?

A

assist in securing agreements between nations to help conserve animals

67
Q

Conservation Agreements

What did the IUCN create?

A

CITES = a treaty regulating the international trade of wild plant and animal specimens and their products

68
Q

Conservation Agreements

What was the Rio Convention?

A

In 1992 when 172 nations created the Earth Summit, a meeting resulting in conservation agreements between countries

69
Q

Conservation Agreements

What is the countryside stewardship scheme?

A

UK govt offer payments to farmers and other land managers to enhance and conserve the English landscape

70
Q

Conservation Agreements

What are some specific aims of the countryside stewardship scheme?

A
  • sustain beauty
  • improve wildlife habitats
  • improve opportunities for countryside enjoyment
  • restore neglected land
71
Q

Sampling techniques

What is a pooter?

A

used to catch small insects by sucking on a mouthpiece to draw insects into a chamber

72
Q

Sampling techniques

What can sweep nets catch?

A

insects

73
Q

Sampling techniques

What do pitfall traps catch?

A

catch small crawling invertebrates, like beetles, spiders, slugs

74
Q

Sampling techniques

How do pitfall traps work?

A

a hole is dug into the ground which insects fall into. It is covered with a roof-structure so the trap doesn’t fill with rain

75
Q

Sampling techniques

What is tree beating?

A

a white cloth is stretched under a living tree/bush. It is then shaken, dislodging animals onto the sheet

76
Q

Sampling techniques

What is kick sampling?

A

A river bank and bed is kicked to disrupt the substrate. A net is then held down stream to capture any organisms released

77
Q

Sampling techniques

What is used to sample plants/slow moving animals?

A

quadrats

78
Q

What is a point quadrat?

A

a frame of a horizontal bar. At set intervals along the bar, long pins can be pushed through the bar to reach the ground. Each species of plant the pin touches is recorded

79
Q

What is a frame quadrat?

A

a square frame divided into a grid of equal section

80
Q

What are the 3 main sample ways of using frame quadrats?

A
  • density
  • frequency
  • percentage cover
81
Q

How are frame quadrats used to sample density?

A

If individual plants can easily be seen, count the number of them in a quadrat to get density per square metre

82
Q

How are frame quadrats used to sample frequency?

A

Can use the small squares in a quadrat to count the number of squares a species is present in

83
Q

How are frame quadrats used to sample percentage cover?

A

Used for speed as lots of data can be quickly collected. It is useful when species are abundant and hard to count by estimating the area within a quadrat

84
Q

Why is it hard to estimate animal population size?

A

They constantly move

85
Q

What is the capture-mark-release-recapture technique?

A

Capturing and marking as many organisms as possible. Then releasing them, allowing time for them to redistribute in habitat before recapturing and comparing figures

86
Q

What does the greater number of marked individuals recaptured mean?

A

The smaller the population

87
Q

What are abiotic factors?

A

non-living conditions in a habitat that have a direct impact on organisms

88
Q

What are the advantages of being able to quickly measure abiotic factors?

A
  • rapid changes can be detected
  • human error is reduced
  • high degree of precision
  • data can be stored and tracked on a computer

A-level Biology (23 decks)

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