Biodiversity Flashcards
1
Q
what is the definition of biodiversity?
A
the variety of living organisms in an area, including:
- habitat biodiversity
- species biodiversity
- genetic biodiversity
2
Q
what the definition of a habitat?
A
the area inhibited by a species
3
Q
what is habitat biodiversity?
A
the number of different habitats in an area
4
Q
what factors does habitat biodiversity include? (include examples)
A
- physical factors (e.g. soil, temperature range)
- living (biotic) factors (e.g. the availability of food, the presence of predators)
5
Q
name 4 examples that could contribute towards habitat biodiversity
A
- sand dunes
- woodland
- meadows
- streams
6
Q
what is the definition of a species?
A
a group of similar organisms able to reproduce to give fertile offspring
7
Q
what is species biodiversity?
A
a measure of species richness and species evenness in an area
8
Q
what is the definition of species richness?
A
the number of different species present in an area
9
Q
what is the definition of species evenness?
A
the number of each species present in an area
10
Q
what does high species richness and evenness tell us about a habitat?
A
it has high biodiversity
11
Q
name a habitat that has species biodiversity (high species richness and evenness)
A
a woodland (could contain many species of plants, insects, birds and mammals)
12
Q
how do you calculate species biodiversity?
A
Simpson’s Index of Diversity
13
Q
what is Simpson’s Index of Diversity?
A
- a measure of species biodiversity within 1 habitat
- it usually includes both species richness and evenness so is considered pretty accurate
- it is always a value between 0 and 1
- the closer the index is to 1, the more diverse the habitat is and the greater its ability to withstand change - it has higher species richness and evenness
14
Q
what is the formula of Simpson’s Index of Diversity?
A
D = 1-(Σ(n/N)²)
D - Simpson’s Diversity Index value (always a value between 0 and 1)
Σ - sum of
n - number of individuals of a species
N - total number of all individuals of all species present
15
Q
what is genetic biodiversity?
A
the variation of alleles within a species or a population of a species (how varied the gene pool is)
16
Q
what is the definition of an allele?
A
a version of a gene
17
Q
what is an example of genetic biodiversity?
A
different breeds of dog (due to a variation in alleles)
18
Q
what is the importance of genetic diversity?
A
- it increases the likelihood of a population adapting to and surviving a change in environment
- it reduces the likelihood of the entire population being wiped out because of a single event (e.g. disease, natural disaster)
- it reduces the vulnerability of a population and increases how robust it is
- it reduces inbreeding (reducing risk of genetic diseases)
- it increases the gene pool and therefore different alleles that could be useful
19
Q
name 4 examples of low genetic diversity
A
- Irish potato famine - airborne fungus wiped them out for 6 years
- pedigree dogs - bred for desirable characteristics, narrowing the gene pool via selective breeding
- Amish people
- ‘blue Fugates’ family (blue people) - inbreeding and intermarriage increases homozygosity, creating a genetic blood condition (blood is chocolate brown causing skin to appear blue)
20
Q
what is the definition of polymorphism?
A
a locus that has 2 or more alleles with a frequency of over 5% in the population
21
Q
what is the definition of a locus?
*
A
a position on a chromosome where alleles of the same gene are found
22
Q
what can polymorphism indicate?
A
it is a great indicator of diversity
(the higher the level of polymorphism, the more frequently different alleles are found within the population, the more genetic diversity)
23
Q
name an example of polymorphism
A
the Heliconius Erato butterfly has a high degree of polymorphism for genes encoding wing colour
24
Q
how can polymorphism be maintained?
A
by a balance between variation, created by new mutations and natural selection
25
how do you measure genetic diversity?
by the proportion of polymorphic gene loci in a population
26
what is the formula for calculating the proportion of polymorphic gene loci?
P = number of polymorphic gene loci ÷ total number of loci investigated (x100 for a %)
27
what is the definition of a genetic drift?
a variation in the frequency of different genotypes in a small population, because of random fluctuations in allele frequency
28
what can a genetic drift cause?
- the disappearance of certain alleles (usually rarer ones), especially after an event such as a natural disaster or a genetic bottleneck
- a new population which is genetically distinct from the original population (possibly evolving to new species)
29
what is the genetic bottleneck effect?
where a sudden event drastically reduces population size, usually resulting in a new population that is much more vulnerable to distinction that the previous
30
name 4 events that could occur, leading to the bottleneck effect
- disease
- a change in environment
- famine (loss of food)
- a natural disaster
31
name 7 pieces of equipment that can be used to collect data on moving organisms and what organism it can be used on
- tree sampling = organisms that live in trees
- pitfall trap = nocturnal invertebrates
- tullgren funnel = organisms found in soil
- light trap = nocturnal flying insects
- sweep netting = insects
- pooters = terrestrial invertebrates
- mark and recapture
32
how do you carry out tree sampling?
shake the tree and see what organisms fall
33
how do you carry out a pitfall trap?
1. dig a hole and place a trap (bucket/container) below ground level
2. cover with a piece of wood (so that water and predators cant enter)
3. leave overnight and count number of organisms
34
how does a tullgren funnel work?
a light is placed above leaf litter which covers a filter, leading to a collecting pot
small organisms move away from the heat/light and land in the collecting pot for investigators to count
35
how does a light trap work?
nocturnal flying insects (e.g. moths) are drawn to light which allows them to gather in one place, ready to be counted
36
what is a pooter and how does it work?
its a small jar that has two tubes - one that goes into your mouth so you can apply suction, and another that goes over the insect so that its sucked into the jar
fine mesh is placed over the end of the first tube to stop you swallowing the insect
37
why is mark and recapture an effective technique?
it ensures you don't count the same organism twice
38
name 3 ways that data can be collected on stationary organisms (plants)
- point frames
- quadrats
- recording percentage cover or a tally
39
how are point frames and quadrats used?
1. place them randomly on the floor of the habitat you are studying using a random number generator (avoiding bias) 2. record the number of different species or count the number of individuals of each species within the quadrat/frame
3. repeat the process to gather as many samples as possible
4. multiply your data collected by the size of the habitat to calculate an estimate population of the entire habitat
40
what are the benefits of collecting sample data and not data from the entire habitat?
- less time consuming
- less logistical issues (e.g. size of habitat, number of people needed)
- less expensive (e.g. equipment, workers)
- interrupts less of the habitat
41
what are the negatives of taking sample data?
- it may not be an accurate representation of the entire habitat
- it may cause habitat destruction and potential disturbance
42
how can you ensure that your collected sample data is representative of the whole habitat?
- collect as many repeats as possible (minimizing the effect of anomalous data and increasing accuracy)
- using random sampling (avoiding bias - the investigator cant pick the spot with the most interesting or predicted results)
- ensure the data is collected as accurately as possible
43
what is random sampling?
taking measurements from random locations within the habitat
this ensures that each sample site has the same probability of being chosen to avoid bias
44
what are the benefits of random sampling?
- it avoids bias
- it increases validity of the results
- it allows the investigator to be more confident in their findings
- the results have a higher chance of accurately representing the entire habitat
45
what is an example of using random sampling?
using a number generator to randomly select the co ordinates that your equipment should be placed within the habitat
46
what is non-random sampling?
taking measurements from non-random locations within the habitat
47
why do we sometimes need to use non-random sampling?
sometimes, there may be a lot of variety in the distribution of a species in the habitat
therefore, you will want to ensure that all the different areas/species are sampled
48
name the 3 types of non-random sampling techniques
- systematic sampling
- opportunistic sampling
- stratified sampling
49
what is systematic sampling?
when samples are taken at fixed intervals, often along a line
50
name 2 examples of systematic sampling
- interrupted/continuous line transect - record the plants that touch the transect at specific distances/continuously
- (interrupted) belt transect - record what is found in each quadrat, placed alongside the transect (at regular intervals)
51
what is opportunistic sampling?
when the samples are chosen by the investigator, usually due it being the best/easiest place to sample
52
what is a benefit to opportunistic sampling?
it is simple to carry out
53
what is a negative to opportunistic sampling?
it is bias and unreliable
54
name an example of opportunistic sampling
placing a quadrat where you know the data will match your hypothesis
55
what is stratified sampling?
when different areas in a habitat are identified and samples are taken separately from each
56
name an example of stratified sampling
when heath and gorse areas are sampled separately in a heathland, according to how much of each there was in the habitat
57
what is proportionate stratified sampling?
when the number of samples per group represents the size of each strata/group
e.g. 80m² = 8 samples, 40m² = 4 samples, 10m² = 1 sample
58
what 3 factors (in the spec) effect biodiversity?
- population growth
- agriculture/monoculture
- climate change
59
how does human population growth effect biodiversity?
as it increases in size, biodiversity decreases due to:
- habitat loss (we need land for housing and producing food)
- over-exploitation (greater demand for resources means we use them up faster than we can replenish them, affecting species e.g. fish)
- urbanization (cities and roads can isolate species, preventing them from interbreeding)
- pollution (increased waste and high levels of pollutants can kill species/their habitats)
60
how does agriculture/monoculture effect biodiversity?
as it increases in size, biodiversity decreases due to:
- habitat loss (they are cleared to make way for things like large crop fields and marine fish farms)
- loss of local plants and animals (due to pesticides and herbicides)
- loss of heritage varieties (traditional crops are lost as they don't make enough money)
61
how does climate change effect biodiversity?
climate change...
- changes average temperature
- changes rainfall patterns
- increases greenhouse gas emissions
- causes global warming
these changes in environmental conditions may make some habitats uninhabitable, causing species to become extinct, reducing biodiversity
however, some species may just migrate to a habitat more suitable, increasing biodiversity in some areas
62
what is the definition of a keystone species?
a species that many other species depend on for survival
63
why are keystone species important?
- they are often predators so keep the population of prey in check
- they can be modifiers - maintaining the environment needed
64
what are the 4 reasons for maintaining biodiversity?
- ecological reasons
- economic reasons
- aesthetic reasons
- ethical reasons
65
what are the ecological reasons to maintain biodiversity?
- protecting species (as the loss of just one can lead to disruption of food chains and nutrient cycles)
- maintaining genetic resources (like crops, plants, micro-organisms as they could be used for medicines, industrial processes, food, clothes etc)
- maintaining ecosystems (interdependence)
- maintaining food chains
66
what are the economic reasons to maintain biodiversity?
- maintaining genetic resources (for food, drink, clothes, fuel etc)
- reducing soil depletion (reducing the cost on fertilizers etc)
- specific organisms have useful potential (e.g. wood for furniture or paper)
- source of income from tourism
- potential resource for non-medical research
67
what are the aesthetic reasons to maintain biodiversity?
- brings joy/pleasure/sense of wellbeing
- can provide opportunities for tourism in developing countries
- provides pleasant landscapes
68
what are ethical reasons to maintain biodiversity?
- we have a responsibility to ensure all organisms are able to survive
- they have the right to survive
- the need to preserve biodiversity for the likelihood of indigenous people/future generations
69
name 4 benefits to agriculture of maintaining biodiversity
- creates a source of food
- creates a source of natural predators to pests
- allows us to breed in disease resistance
- creates a source of plant varieties for cross breeding
70
how do we maintain biodiversity?
conservation
71
what is the definition of conservation?
the protection and management of species and habitats
72
what are the 2 types of conservation?
- in situ
- ex situ
73
what is in situ conservation?
- conservation on site
- it involves protecting species and habitats
74
what are the methods of in situ conservation?
- establishing protected areas (e.g. wildlife reserves) to restrict urban development
- controlling/preventing species that threaten local biodiversity (e.g. grey squirrels in Britain)
- protecting habitats (e.g. trimming trees)
- restoring damaged areas (e.g. coastlines polluted with oil spills)
- promoting particular species (e.g. by providing nesting sites)
- making it illegal to kill endangered species
75
what are the advantages to in situ conservation?
- often both the species and the habitat is conserved
- its less disruptive (you don't have to remove the species from its habitat)
- larger populations can be protected
- the chances of the population surviving are greater than with ex situ methods
76
what are the disadvantages to in situ conservation?
- it can be difficult to control some factors that are threatening a species (e.g. poaching, predators, disease, climate change)
77
name 2 examples of in situ conservation
- marine conservation zones
- wildlife reserves
78
what is ex situ conservation?
- conservation off site
- it involves protecting a species by removing part of the population from a threatened habitat and placing it in a new location
- it is often used as a last resort
79
what are the methods of ex situ conservation?
- relocating an organism to a safer area
- breeding organisms in captivity then re introducing them into the wild when they are strong enough (e.g. zoos)
- botanic gardens (controlled environments used to grow a variety of rare plants, which can then be reintroduced into suitable habitats)
- seed banks (where seeds are frozen and stored without losing their fertility)
80
what are the advantages of ex situ conservation?
- it can be used to protect individual animals in a controlled environment
- things like predation and hunting can be managed more easily
- competition for resources can be reduced
- easy to check for and treat diseases
- breeding can be manipulated
- it can be used to reintroduce species that have left an area
81
what are the disadvantages of ex situ conservation?
- usually only a small amount of individuals can be cared for
- can be difficult and expensive to create and sustain the correct environment
- habituated animals that are used to human contact may not cope in the wild
- usually less successful than in situ as they may not breed successfully or adapt well to their new environment
82
name 3 examples of ex situ conservation
- zoos
- seed banks
- botanic gardens
83
what does successful reintroduction rely on?
- limited human contact
- ensuring only healthy and genetically varied species are released
- training animals to hunt for food (self-reliant)
- gradual reintroduction
- ensuring food is available in new habitat
- preventing hunting/predation
- monitoring the population
- raising public awareness and educating local people
84
why are there conservation agreements put in place?
- conservation is much more likely to be successful when countries/areas work together
- information about threats to biodiversity needs to be shared between countries so that successful conservation methods can be put in place
85
what are 2 international conservation agreements?
- Rio Convention on Biological Diversity (CBD)
- Convention on International Trade in Endangered Species (CITES agreement)
86
what are the aims of CBD/what has it already done?
- to develop international strategies on the conservation of biodiversity and how to use animal and plant resources in a sustainable way
- to provide guidance to governments on how to conserve biodiversity
- it has already made it part of an international law that conserving biodiversity is everyone's responsibility
87
what are the aims of CITES/what has it already done?
- to increase international cooperation in regulating trade in wild animals and plant specimens
- to help conserve species by limiting trade (e.g. of fur, skins, horns) through licensing and laws
- to raise awareness of threats of biodiversity through education
- its member countries have already agreed to make killing endangered species illegal
88
what is a local (UK) conservation agreement?
The Countryside Stewardship Scheme (CSS)
(introduced in 1991)
89
what are the aims of CSS/what has it already done?
- to conserve wildlife biodiversity
- to improve, extend and create wildlife habitats by promoting management techniques to landowners (e.g. by paying them to not cut back meadows and hedgerows)
- to increase countryside enjoyment
