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Biology A level > 4.2.1 - Biodiversity > Flashcards

4.2.1 - Biodiversity Flashcards

1
Q

Biodiversity

A

Measure of how varied life on earth is

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2
Q

3 types of biodiversity

A

Habitat
Species
Genetic

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3
Q

Genetic diversity

A

Measure of how many variations that are in the genetic code between individuals in spp. or diff spp

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4
Q

Species diversity

A

Measure of how many diff species are present

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5
Q

Species

A

Share common physiological, anatomical and behavioural characteristics
Can interbreed to produce fertile offspring

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6
Q

Hybrid

A

Produced by diff species but are infertile

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7
Q

Community

A

Several populations of diff spp living in a habitat at a certain time

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8
Q

Habitat

A

Place where organisms live at a certain time

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9
Q

Population

A

The amount of spp living in a habitat at a certain time

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10
Q

Endemism

A

Group of organisms unique to one particular habitat (geographically discrete)

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11
Q

Things to consider when sampling

A

Size of samples
No. of samples
Sampling technique used
Ways to not disturb the habitat

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12
Q

Random sampling

A

Uses a calculator to generate random numbers which can be used as coordinates on an imaginary grid

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13
Q

Opportunistic sampling

A

Involves using prior knowledge to select sample sites or changing the sampling strategy on site

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14
Q

Stratified sampling

A

Involves carrying out samples in each recognisable sub-habitat

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15
Q

Systematic sampling

A

Involves carrying out sampling at fixed intervals in each distance

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16
Q

Methods of using quadrats

A

Point sampling - counting species touching quadrat

Grid sampling - estimating how many smaller squares are occupied by each species

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17
Q

Methods to sample animals

A

Longworth trap (mark, release, recapture)
Observation
Pitfall trap
Tullgreen funnel (invertebrates living in leaf litter)
Sweep net and kick sampling
Pooters
Tree beating

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18
Q

Measures of species diversity

A

Species richness

Species evenness

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19
Q

Species richness

A

No. of diff types of species in a particular area. The greater the number of spp, the ‘richer’ the area

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20
Q

Species evenness

A

How evenly each species is represented throughout a habitat

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21
Q

What does a high Simpson’s index indicate

A

Habitat with high diversity
High species evenness and richness
May survive disruption (introduction of new disease or competition)
Should be conserved

22
Q

When is genetic diversity increased

A

When there is more than one gene variant (allele) for a particular locus

23
Q

Factors affecting biodiversity

A

Human population growth
Increasing use of agriculture (monoculture)
Climate change

24
Q

Reasons for maintaining biodiversity

A

Ecological
Economic
Aesthetic

25
Ecological reasons for maintaining biodiversity
Regulation of O2 and CO2 in the atmosphere Soil formation and retention Protecting keystone species Maintaining genetic resource
26
Economic reasons for maintaining biodiversity
Pollination of crops depends on bees Unknown species may be effective medicines Growth of food and timber relies on correct functioning of ecosystem To avoid soil depletion (continuous monoculture) Natural predators to pests reduce the need for pesticides
27
Aesthetic reasons for maintaining biodiversity
Maintaining the landscape Being around nature relives stress and helps recovery from injury A healthy, well-balanced ecosystem is complex and beautiful
28
Types of conservation
In situ | Ex situ
29
In situ conservation
Conserving a species in its natural habitat by creating marine conservation zones and wildlife reserves
30
Advantages of in situ conservation
Tourism generates money Generates jobs for locals Both habitats and species are conserved Organisms will behave normally
31
Disadvantages of in situ conservation
Can be difficult to monitor organisms and ensure they're healthy Poachers/hunters The environmental factors that caused the decline may still be present Difficult to treat diseases
32
Ex situ conservation
Conserving a species using controlled habitats away from its normal environment e.g. seed banks, botanic gardens and zoos
33
Advantages of ex situ conservation
Easy research Diseases can be controlled Controlled breeding Once populations have been increased, some can be reintroduced to the wild Seed banks can store seeds of millions of rare/extinct plants using a smaller area
34
Disadvantages of ex situ conservation
Organisms living in unnatural habitat (effects on behaviour) May not breed Little point in conserving individuals if their natural habitat is lost and there nowhere to return to
35
Conservation agreements
CITES CBD CSS
36
Keystone species
Is one that has a disproportionate effect on the ecosystem - loss of these species affects many others
37
CITES
Conservation on International Trade in Endangered Species International countries voluntarily agree to ensure their trade of wild animals and plants doesn't affect their survival Prohibit commercial trade on wild plants
38
CBD
Rio Convention on Biological Diversity Promotes development of sustainable resources of food, water and medicine Promotes ex situ conservation measures with shared resources
39
CSS
Countryside Stewardship Scheme | Aims to enhance natural beauty of UK country side and improve public access
40
How does human population growth lead to a decline in biodiversity
Deforestation to build houses, habitats destroyed (lower habitat diversity)
41
How does agriculture lead to decline in biodiversity
Monoculture; only growing one type of crop | Excessive use of pesticides - lower genetic diversity
42
How does the excessive use of farmland cause a reduction in biodiversity
Only promotes growth of one species | Others are outcompeted and die out
43
Why will a reduction in biodiversity present problems for agriculture
Loss of genetic diversity Lost genes may have been useful e.g. gene for drought resistance Fewer pollinators
44
Advantages of seed banks
Not susceptible to diseases Remain viable for longer Requires less space so more can be kept
45
Why are seeds in seed banks collected from several sites
Maintain gene pool Reduce chance of inbrrrding In case there are environmental factors affecting one of the sites
46
Why is it bad for endangered species to be isolated
Small gene pool More vulnerable to predators and poachers Natural disaster could wipe out part of population
47
How can zoos help endangered animals if captive breeding doesn’t work
Raise awareness | Promote conservation projects
48
Niche
Organisms role in the habitat its living in
49
How will having smaller fields increase biodiversity
More hedges in between the fields, species can live there
50
Why might deforestation increase biodiversity in the short term
Many species are forced to live in a small area | After a while however, the woodland will reach its carrying capacity and organisms either migrate or die
51
Requirements to use Spearmans rank
Paired data More than 5 data points Independent of each other Ordinal/interval data
52
Advantages of standard deviation vs range
Less affected by outlier | Takes into account every value

Biology A level (32 decks)

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