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Biology a level - ocr a > Chapter 11 - Biodiversity > Flashcards

Chapter 11 - Biodiversity Flashcards

1
Q

What are the 3 different levels of biodiversity

A

Habitat diversity
Species diversity (species richness, species eveness)
Genetic diversity

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2
Q

What is habitat biodiversity

A

The number of different habitats in an area

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3
Q

What is species diversity

A

Species richness
The number of different species in an area

Species eveness
The number of individuals present in each species in an area

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4
Q

what is Genetic diversity

A

The variation of alleles within a species

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5
Q

Species definition

A

Group of similar organisms that are able to reproduce to give fertile offsprings

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6
Q

Habitat définition

A

Area inhibited by living organisms (species)

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7
Q

Biodiversity definition

A

The variety of living organisms in an area

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8
Q

What can sampling be used for

A

MEASURE BIODIVERSITY
To estimate the number of organisms in an area
To estimate the abundance and distribution of an organism
To measure a particular characteristic of an organism

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9
Q

What is random sampling and why

A

Selecting individuals by chance

This avoids bias
More representative of the actual area

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10
Q

Examples of random sampling

A

Dividing a field into a grid

Using random number generator to coordinates

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11
Q

What is non random sampling

A

Sample is not chosen at random

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12
Q

Three main non-random sampling techniques

A

Stratified
Systematic
Opportunistic

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13
Q

What is the systematic technique

Example

A

Samples taken at fixed intervals

Quadrants placed along a transect at fixed intervals

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14
Q

What is stratified sampling

Example

A

Different areas in the habitat are identified and sampled separately

Population divided into subgroups based on characteristics
Sample is taken from each strata, proportional to its size

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15
Q

What is opportunistic sampling

Example

A

The area is chosen by the leader

Simple
Organisms are conveniently available
Safe

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16
Q

Why is sampling never truly reliable

Why isn’t it truly representative of the organisms present

A

Bias

  • more interesting areas may be chosen
  • reduces by random sampling

Chance
- reduce by doing a larger sample

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17
Q

What are 5 Techniques used to collect animals for study

5

A 
Pooter
Sweep nets 
Pitfall traps 
Tree beating 
Kick sampling
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18
Q

What is a pooter

Used to catch
And how

A

Small insects

Sucking on mouthpiece to draw insects up into holding chamber via inlet tube

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19
Q

What is a sweep net

Used to catch
And how

A

Flying insects

Sweep the net and catch them

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20
Q

What is tree beating

Used to catch
And how

A

Invertebrates living in trees

White cloth stretched under tree to catch invertebrates
Tree is kicked and shaken

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21
Q

What is a pitfall trap

Used to catch
And how

A

Small crawling invertebrates

Hole dug in ground with roof placed on top
Invertebrates fall into hole

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22
Q

What is kick sampling

Used to catch
And how

A

Organisms living in water

Net held downstream
River bank kicked to disturb substrate
Organisms caught in net

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23
Q

What is a tullgren funnel

Used to catch
And how

A

Used to collect insects from soil

Sample placed in sieve over a funnel
Light above dries and warms the soil
Causing animals to move downwards and fall through sieve into funnel

Dish contains ethanol to stop escape

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24
Q

What are quadrats used for

Name the 2 type of quadrats

A

Used to sample plants
To pinpoint an area that should be sampled
Sample small slow animals

Point quadrat
Frame quadrat

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25
Q

What is a point quadrat

A

Frame with horizontal bar containing holes at intervals

Pins pushed into holes and soil

Species of plant that touches the pins is recorded

26
Q

what is a Frame quadrat

A

Square frame divided into grids

Count type and number of species in each section

27
Q

3 different ways to use a quadrat

Measuring by:

A

Density:

  • if plants can be seen clearly
  • count number of them

Frequency

  • hard to count
  • count number of squares species is present
  • percentage

Percentage cover

  • abundant
  • estimate by eye percentage of quadrat it covers
28
Q

How to estimate plant population size

Quadrat

A

Take many samples
Calculate mean of individual results
Find total population of organism in area
Multiply by total area

29
Q

Estimating animal population

A

Compare the number of marked and unmarked organisms

More marked = lower population

30
Q

What does Simpson’s index of diversity do

A

Measures biodiversity

Takes into account species richness and evenness
Value between 0-1
No diversity - infinite diversity

31
Q

Simpson’s index of diversity

Formula

A

1 - sum of (species evenness / total number of organisms)2

Do for each species
Add together
Minus from 1

32
Q

Why is genetic biodiversity important

A

A variety of alleles means species can adapt to changes in their environment
Likely to be an organism with an advantageous gene
Enabling them to survive changing environments
Not become extinct
Share the advantageous gene

33
Q

How to increase genetic biodiversity

A

Mutations
Create new alleles

Gene flow
Alleles transferred between different populations

34
Q

Decreasing genetic biodiversity

A

Selective breeding
- only few individuals allowed to breed for advantageous gene

Captive breeding

  • few animals available for breeding
  • less alleles shared

Artificial cloning

Natural selection
- disadvantageous alleles die

Genetic bottleneck
- large number die before reproducing

Founder effect
- few individuals colonisé to new area

Naturally disappear

35
Q

When are biodiversity levels low

A

Zoos = captive breeding

Rare breeds

Pedigree animals

36
Q

What are rare and pedigree animals

A

Rare
- animal not used in large scale farming

Pedigree
- been bred purely from animals of the same breed

37
Q

What is polymorphism

A

Describes a locus with 2 or more alleles

38
Q

Formula used to measure genetic diversity

A

Proportion of polymorphic gene loci =

Number of polymorphic gene locis / total number of locis

39
Q

3 factors that affect global biodiversity

A

Human growth
Agriculture
Climate change

40
Q

How does human population growth affect biodiversity

A

Habitat loss from development

  • decreases habitat diversity - decreases species diversity
  • isolate species so they can’t interbreed = decreases genetic diversity

Over exploitation - deforestation

  • resources used up faster than can be replenished
  • decreases habitat diversity - decreases species diversity

Pollution
- decreases species

41
Q

How does agriculture decrease biodiversity

A

Monoculture

  • decreases genetic diversity
  • species diversity

Clearing land

  • decreases habitat diversity
  • decreases plant species
42
Q

How does climate change affect biodiversity

A
  • areas will get hotter, colder, drier, wetter
  • causes low areas of biodiversity to struggle = decreases species
  • migration to other areas = decreases species
  • new plants may grow = increase species
43
Q

What are the ecological reason for maintains biodiversity

A

To protect species including keystone species

To maintain genetic diversity

44
Q

Why is protecting species and keystone species important for ecological reasons

A

Organisms in a ecosystem are interdependent

  • disruption of food chains
  • disruptions of nutrient cycle - decomposers recycle nutrients into solid, grow plants, animals feed off of
45
Q

What are keystone species

A

Species which many of the other species depend on, whom without the ecosystem would change

Predators
Modifiers - maintaining environment needed for ecosystem (beavers-dams)
Hosts - plants that provide a particular environment

46
Q

Why is maintain genetic resources important for ecological reasons

A

Provide us with everyday products (food,drugs,clothes,medicine,fuels)

Allow us to adapt to changes in environment
- to genetically engineer drought resistant crops

47
Q

Why is reducing soil depletion important for economic reasons

A

Reduce soil depletion by

Rotating crops with other crops so that the nutrients and organic matters can be replaced = increases biodiversity

Soil depletion costs

  • buying fertilisers
  • lower yields
48
Q

Why is protecting biodiversity important for aesthetic reasons

A

Pleasant to look at
Beautiful landscapes
Attract more visitors

49
Q

What is insitu conservation

A

On site conservation

50
Q

Methods of insitu conservation

A

National parks, marine conservation zones = established areas
- stopping urban development, hunting, farming

Controlling or prevent the introduction of threading species

Giving legal protection to endangered species

Protecting habitats - controlling water levels

Promoting species - protecting food, nesting sites

51
Q

What is exsitu conservation

A

Off site conservation

52
Q

Advantages of insitu conservation

A

Conserved in their natural habitat
Less disruptive than removing removing from habitat
Natural and cultural heritage protected

53
Q

Disadvantages of insitu

A

Genetic diversity may have already been decreased

Diseases and inter specific threats still present

Poachers may cause damage

54
Q

Methods of exsitu conservation

A

Relocating to safer area

Breeding in captivity than releasing into nature

Botanic gardens

Seed banks

55
Q

Advantages of exsitu conservation

A
  • protect individual animals in a controlled environment
  • completely protected from predators poaching
  • genetic diversity can be managed
  • used for education
56
Q

Disadvantages of exsitu

A 
Limited genetic diversity 
Living outside of natural environment 
Expensive 
Only small number of animals 
Don’t adapt to new environment 
Catch diseases from humans
57
Q

International agreements to protect species and habitats

A

Rio convention of biological diversity (CBD)

CITES agreement

58
Q

What does the Rio convention of biological diversity (CBD) do

A

Aims to use animal and plant resources in a sustainable way

Provides guidance to governments on how to conserve biodiversity

Made an international law that biodiversity is everyone’s responsibility

59
Q

What does the CITES agreement do

A

Increases international cooperation in regulating trade

Illegal to kill an endangered species

Limiting trade through licensing

Illegal to trade parts from endangered species

Raise awareness = education

60
Q

Local conservation agreements

A

The countryside stewardship scheme (CSS)

61
Q

What does The countryside stewardship scheme (CSS) do

A

Conserve wildlife and biodiversity

Promotes specific management techniques to landowners

10 year agreements to pay landowners that follow these management techniques
- increases habit and species diversity

Biology a level - ocr a (11 decks)

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