Biodiversity Flashcards
(84 cards)
1
Q
Different levels at which biodiversity can be measured
A
Habitat biodiversity, genetic biodiversity, species biodiversity
2
Q
Habitat biodiversity
A
Number of different habitats found within an area
3
Q
Species biodiversity
A
Made of species richness and evenness
4
Q
Species richness
A
Number of different species living in a particular area
5
Q
Species evenness
A
Comparison of the number of individuals of each species living in a community
6
Q
Community
A
All the populations of living organisms in a particular habitat
7
Q
Genetic biodiversity
A
Variety of genes that make up a species
8
Q
Sampling
A
Taking measurements of a limited number of individual organisms present in a particular area
9
Q
Uses of sampling
A
To estimate the number of organisms in an organism, to measure a particular characteristic of an organism
10
Q
Types of sampling
A
Random, non-random
11
Q
Random sampling
A
Selecting individuals by chance, each individual has an equal likelihood of selection
12
Q
How to carry out a random sample
A
Make grid with tape measures, use random numbers to determine x coordinate and y coordinate, take sample at each coordinate pair
13
Q
Types of non-random sampling
A
Opportunistic, stratified, systematic
14
Q
Opportunistic sampling
A
Using organisms that are readily available
15
Q
Weakest form of non-random sampling
A
Opportunistic
16
Q
Why is opportunistic sampling the weakest form of non-random sampling?
A
Not representative
17
Q
Stratified sampling
A
Dividing a population into strata based on a characteristic, random sample taken from each strata proportional to size
18
Q
Systematic sampling
A
Identifying different areas within an overall habitat which are then sampled separately (Transects)
19
Q
Line transect
A
Marking a line along the ground between the poles and taking samples at specific points
20
Q
Belt transect
A
Two parallel lines marked, samples taken of the area between the two lines
21
Q
Why is a sample never truly representative?
A
Sampling bias, chance
22
Q
How to reduce sampling bias
A
Random sampling
23
Q
How to reduce effect of chance
A
Large sample size
24
Q
Sampling methods
A
Pooters, sweep nets, pitfall traps, tree beating, kick sampling, quadrats
25
Types of quadrats
Point, frame
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Point quadrats
Frame containing a horizontal bar, long pins can be pushed through the bar, each species of plant that the pin touches is recorded
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Frame quadrats
Square frame divided into grid of equal sections, type and number of species within each section is recorded
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How to measure species richness
Use sampling method, compile list of species identify, keys used to identify species
29
Different things you can measure with frame quadrats
Density, frequency, percentage cover
30
How to do capture-mark-release-recapture
Capture as many individuals of a species as possible, organisms marked and released, time is allowed for organisms to redistribute, another sample collected, compare number marked and unmarked in second sample, if lots are marked you have a small sample
31
How to measure species evenness using capture-mark-release-recapture
Compare the total number if each organism present
32
Simpson's Index of Biodiversity
Measure of biodiversity that takes species richness and evenness into account
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Formula for Simpson's Index of Biodiversity
1- (Sum of total number of organisms of a particular species/ Sum of total number of organisms of all species)^2
34
What a low biodiversity index means
Few successful species, extreme nature, fewer ecological niches, very specific adaptations, relatively simple food webs, change to the environment has a major effect on the ecosystem
35
What a high biodiversity index means
Large number of successful species, more ecological niches, many species, complex food webs, change to the environment has a relatively small effect on the ecosystem
36
Equation for proportion of polymorphic gene loci
Proportion of polymorphic gene loci = Number of polymorphic gene loci/ Total number of loci
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Polymorphic genes
Genes with more than one allele
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Suitable populations for measuring genetic biodiversity
Zoos, rare breeds, pedigree animals
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Factors that affect genetic biodiversity
Mutations, interbreeding
40
Gene flow
When an individual migrates from one population and breeds with a member of another population so alleles are transferred between two populations
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How genetic biodiversity can decrease
Selective breeding, captive breeding programmes, rare breeds, artificial cloning, natural selection, genetic bottlenecks, founder effect, genetic drift
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Genetic bottleneck
When few individuals within a population survive an event, reducing the gene pool
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Founder effect
Where a small number of individuals create a new colony which is geographically isolated from the original
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Genetic drift
Random nature of alleles being passed on from parents to their offspring
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Factors affecting biodiversity
Human population growth, agriculture, climate change
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Effect of deforestation on biodiversity
Reduces number of trees present, species diversity reduced, reduces number of animal species present, animals migrate to other areas for survival
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Effect of agriculture on biodiversity
Deforestation, removal of hedgerows reduces number of plant species present and destroys habitats, use of chemicals that reduce species diversity and destroy food source of other organisms, monoculture lowers biodiversity and cause of deforestation
48
Effect of climate change on biodiversity
Melting of polar ice caps leads to extinction of species in those areas, rising sea levels flood low-lying land and reduce available habitats, saltwater reduces habitats of freshwater plants and animals, drought increases dominance of xerophytes insect life cycles change including pollinators which will then affect plants
49
Aesthetic reasons for maintaining biodiversity
Enriching lives (I'm not kidding, apparently this is an acceptable answer), inspiration for musicians and authors, recovery from stress or injury
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Economic reasons for maintaining biodiversity
Soil erosion and desertification as a result of deforestation, conserving organisms we use to make things, medical uses, soil depletion from monoculture, protection against abiotic stresses, tourism, cross breeding
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Ecological reasons for maintaining biodiversity
Interdependence of species, keystone species, maintaining genetic resources
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Keystone species
Species that play a key role in maintaining the structure of an ecological community which is large relative to their abundance
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Conservation
Preservation and careful management of the environment and of natural resources
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Advantages if in situ conservation
Maintains genetic diversity, maintains evolutionary adaptations to enable a species to adapt continually, preserves interdependent species relationships, cheaper
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Active management techniques in wildlife reserves
Controlled grazing to allow species time to recover, restricting human access, controlling poaching, feeding animals, reintroduction of species, removal of invasive species, halting succession
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Succession
When early colonising species of an area are replaced until a stable mature population is achieved
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Methods of in situ conservation
Wildlife reserves, marine conservation zones
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Role of marine conservation zones
To create areas of refuge where populations can build up
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Methods of ex situ conservation
Botanic gardens, seed banks, captive breeding programmes
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How to get seeds ready for storage in seed banks
Dried, stored at temperatures of -20 degrees celsius, slowing down ability to germinate
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How to ensure that genetic diversity is maintained in a captive breeding programme
Catalogue of data produced to ensure matches as different as possible, artificial insemination, embryo transfer, long-term cryogenic storage of embryos
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Issues on release after captive breeding programmes
Loss of resistance to local diseases, new diseases, lack of food, loss of behaviour for looking for food, not scared of humans, genetic makeup so different from original population they can't interbreed, don't breed in the wild, habitat destruction
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3 agreements made in the Rio Convention
Convention on Biological Diversity, United Nations Framework Convention on Climate Change, United Nations Convention to Combat Desertification
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Convention on Biological Diversity
Countries must develop national strategies for sustainable development to ensure biodiversity
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United Nations Framework Convention on Climate Change
Requirement to take steps to stabilise greenhouse gas concentrations in the atmosphere
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United Nations Convention to Combat Desertification
Preventing the transformation of fertile land into desert, reducing effects of drought through programmes of international cooperation
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Countryside Stewardship Scheme
Offering financial incentives for farmers to sustain diversity of a landscape, improve habitats, restore neglected land, conserve historic features and improve opportunities for countryside enjoyment
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Why does higher genetic biodiversity increase a species' chance of long term survival?
Greater genetic variation, more likely to have a gene that confers disease resistance so entire species not wiped out at once, may have adaptation that allows it to catch prey better so less chance of being eaten
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Advantages to using sensors (pH probes, temperature probes) to measure abiotic factors
More precise, data can be stored on a computer, human error reduced, rapid changes detected
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Different things that can be measured to measure species evenness
Percentage cover, frequency, population density
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Advantages of measuring population density to measure species evenness
Accurate
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Disadvantages of measuring population density to measure species evenness
Time consuming, can only be used when individuals of a species can be identified
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Advantages of measuring frequency to measure species evenness
Rapid, can be used when individuals of a species can't be identified
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Disadvantages of measuring frequency to measure species evenness
Approximate result
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Advantages of measuring percentage cover to measure species evenness
Lots of data collected quickly
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Disadvantages of measuring percentage cover to measure species evenness
Least precise method
77
Why is species evenness important in measuring biodiversity?
More quantitative than species richness, used to calculate Simpson's Index of Biodiversity
78
Why is it likely that our estimates of species richness are underestimates?
Not all areas explored, microscopic species are hard to see
79
CITES
Convention on International Trade in Endangered Species
80
Aims of CITES
Monitor trade in endangered species, ensure trade doesn't endanger wild populations, prohibit trade in wild plants
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Aim of Rio Convention in Biological Diversity
Sustainable use of organisms, share genetic resources, share access to scientific knowledge
82
How to ensure the success of release programmes after captive breeding
Healthy before release, provide food, make sure the reserve is protected, monitor the population, raise public awareness
83
Why are seeds dried before storage?
Stops enzymes working, no hydrolysis, no germination of seeds
84
Why is it better to store seeds than adult plants?
Can be collected without damaging plants, take up less space so more can be stored, cheaper to transport and store, remain viable for longer time periods, less susceptible to disease
