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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
What is a point quadrat
Frame with horizontal bar containing holes at intervals Pins pushed into holes and soil Species of plant that touches the pins is recorded
26
what is a Frame quadrat
Square frame divided into grids Count type and number of species in each section
27
3 different ways to use a quadrat Measuring by:
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
How to estimate plant population size Quadrat
Take many samples Calculate mean of individual results Find total population of organism in area Multiply by total area
29
Estimating animal population
Compare the number of marked and unmarked organisms More marked = lower population
30
What does Simpson’s index of diversity do
Measures biodiversity Takes into account species richness and evenness Value between 0-1 No diversity - infinite diversity
31
Simpson’s index of diversity Formula
1 - sum of (species evenness / total number of organisms)2 Do for each species Add together Minus from 1
32
Why is genetic biodiversity important
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
How to increase genetic biodiversity
Mutations Create new alleles Gene flow Alleles transferred between different populations
34
Decreasing genetic biodiversity
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
When are biodiversity levels low
Zoos = captive breeding Rare breeds Pedigree animals
36
What are rare and pedigree animals
Rare - animal not used in large scale farming Pedigree - been bred purely from animals of the same breed
37
What is polymorphism
Describes a locus with 2 or more alleles
38
Formula used to measure genetic diversity
Proportion of polymorphic gene loci = Number of polymorphic gene locis / total number of locis
39
3 factors that affect global biodiversity
Human growth Agriculture Climate change
40
How does human population growth affect biodiversity
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
How does agriculture decrease biodiversity
Monoculture - decreases genetic diversity - species diversity Clearing land - decreases habitat diversity - decreases plant species
42
How does climate change affect biodiversity
- 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
What are the ecological reason for maintains biodiversity
To protect species including keystone species To maintain genetic diversity
44
Why is protecting species and keystone species important for ecological reasons
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
What are keystone species
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
Why is maintain genetic resources important for ecological reasons
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
Why is reducing soil depletion important for economic reasons
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
Why is protecting biodiversity important for aesthetic reasons
Pleasant to look at Beautiful landscapes Attract more visitors
49
What is insitu conservation
On site conservation
50
Methods of insitu conservation
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
What is exsitu conservation
Off site conservation
52
Advantages of insitu conservation
Conserved in their natural habitat Less disruptive than removing removing from habitat Natural and cultural heritage protected
53
Disadvantages of insitu
Genetic diversity may have already been decreased Diseases and inter specific threats still present Poachers may cause damage
54
Methods of exsitu conservation
Relocating to safer area Breeding in captivity than releasing into nature Botanic gardens Seed banks
55
Advantages of exsitu conservation
- protect individual animals in a controlled environment - completely protected from predators poaching - genetic diversity can be managed - used for education
56
Disadvantages of exsitu
``` 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
International agreements to protect species and habitats
Rio convention of biological diversity (CBD) CITES agreement
58
What does the Rio convention of biological diversity (CBD) do
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
What does the CITES agreement do
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
Local conservation agreements
The countryside stewardship scheme (CSS)
61
What does The countryside stewardship scheme (CSS) do
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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