1
Q
what is biodiversity?
A
the variation that exists within and between all forms of life
2
Q
why is biodiversity important in ecosystem resilience?
A
it helps them to resist changes
3
Q
what are the three ways in which biodiversity can be measured?
A
species
habitat
genetic
4
Q
what is habitat diversity?
A
This is the range of different habitats within a particular area or region
5
Q
describe an area with a high habitat biodiversity
A
an area with a large number of different habitats within it
6
Q
what is species diversity?
A
the number of species within an ecosystem
7
Q
what are the two components within species diversity?
A
species evenness
species richness
8
Q
what is species evenness?
A
measures how equally abundant different species are within a community
9
Q
what is species abundance?
A
the total count or density of individuals of a specific species within a defined area or ecosystem
10
Q
what is genetic diversity?
A
the diversity of alleles and genes in the genome of species
11
Q
how is genetic diversity measured?
A
working out the proportion of genes that have more than one form (allele) and how many possible alleles each gene has
12
Q
when is genetic diversity limited?
A
in small/isolated populations
–> Inbreeding in small, isolated populations leads to a high proportion of individuals being homozygous (e.g. AA to aa) for many genes, resulting in lower genetic diversity
This can mean that genetic diseases caused by recessive alleles can become more common
13
Q
what is the distribution of a habitat?
A
where organisms live within a habitat
14
Q
what is the abundance of a habitat?
A
how many organisms are present
15
Q
what are the two types of sampling?
A
random
non-random
16
Q
why must you have a large sample group when sampling?
A
to make the sample truly representative and eliminate the effects of chance
17
Q
how are random sampling areas selected?
A
— a grid system is set up by laying out two long tape measures along the outer edges of a habitat
—a random number generator is used to generate two random numbers
– the numbers are used like graph coordinates, and the sample site is placed at the point of intersection
18
Q
wha are the benefits of random sampling techniques?
A
they void bias
19
Q
on what type of area would random sampling be the best type?
A
When a sampling area is reasonably uniform or has no clear pattern of species distribution
20
Q
what are the three main types of non-random sampling?
A
opportunistic
stratified
systematic
21
Q
what is opportunistic sampling? give an example
A
Sampling is carried out on the basis of opportunity, e.g. sample sites that can be reached quickly and safely are chosen
22
Q
what is stratified sampling? give an example
A
The number of random samples taken within each habitat type is proportional to the area covered by each habitat type
E.g. if 10 % of a dense woodland contains grassy clearings then 90 % of the sample locations should have tree cover and 10 % will be in clear areas
– the survey effort is balanced to match the landscape: larger habitats get more samples, and smaller habitats get fewer, based on their percentage of the total area. This ensures every habitat is represented, avoiding under-representation of small but important areas
23
Q
what is systematic sampling? give an example
A
Samples that are taken across a habitat with reference to the changes in habitat conditions
E.g. sample sites may be taken at:
increasing altitude
increasing distance from the edge of a woodland
increasing distance from the shore line
24
Q
what peace of equipment does systematic sampling include
A
a transect
25
what is a quadrat?
a square frame that is placed within the area to be studied to provide a sample
26
what type of organism are quadrats suitable for?
plants or slow-moving animals
27
what are 4 examples of measurements within a quadrat?
- the number of species present
- the number of individuals of a species present, i.e. species abundance
- the presence/absence of a species
- the percentage cover of a species, e.g. for species where it is difficult to determine where one individual ends and another starts
28
what other species of equipment can be used for sampling?
Sweeping nets
Pitfall traps
Pooters
Transects
29
what is a sweeping net and when is It used?
Sweeping nets
Sweeping, or sweep, nets are large, strong nets made from a material with very small holes
The nets can be swept across vegetation, e.g. grass or tree branches, to catch flying insects and insects that live on leaves
After sampling the insects in the net can be counted and identified
30
what is a pitfall trap and when is It used?
Pitfall traps are cans or jars that are sunk into the ground
Ground-dwelling invertebrates fall into the trap as they walk along the ground, and then cannot climb out again
A lid ensures that the trap does not fill with rainwater
31
what is a pooter and when is It used?
Pooters are small plastic or glass containers with two tubes extending from the lid
The tubes can be used to suck up small invertebrates
The first tube is placed over the insect and the second tube is used by the scientist to create suction
Once inside the container the sampled organisms can be easily viewed and identified
32
what is a transect and when are they used?
a line along which samples can be taken
- used during systematic sampling to assess how abundance and distribution of organisms is affected by changes in abiotic factors across a habitat
33
what are the two types of transect?
belt transect
line transect
34
describe how you would use a line transect?
Lay out a measuring tape in a straight line across the sample area
At regular distances along the tape, e.g. every 1 m, record the identity of the organisms that touch the line
35
describe how you would use a belt transect?
Lay out a measuring tape in a straight line across the sample area
Place quadrats at regular intervals, or continuously, along the tape and record the abundance or percentage cover of each species within each quadrat
36
which methods could you use for selecting sample sites to avoid sampling bias?
a random number generator to choose a set of coordinates
37
why do you need a large sampling area?
the area must be big enough to get a representative estimate for the specific habitat/ecosystem
38
how would you calculate population density from a quadrat?
Place a quadrat at the generated coordinate
Count the number of individuals in each quadrat
39
how would you calculate percentage cover when using a quadrat?
Usually used for plants
Place a grid quadrat (a square frame split into 100 smaller squares) at this coordinate
Each square of a grid quadrat is equivalent to 1% cover
Count the number of squares in each quadrat within which the species occupies over half the square
If 30 squares contain the species, the percentage cover is 30%
40
what is Species density?
how many individuals of that species there are per unit area
41
when would you use percentage cover?
when the individuals are hard to count
42
what is Species frequency and how do you calculate it?
the probability that the species will be found within any quadrat in the sample area
- The number of quadrats that the species was present in is divided by the total number of quadrats and then multiplied by 100
For example, if bluebells were found in 18 out of 50 quadrats the species frequency would be (18/50) x 100 = 36%
43
what are the downsides of using quadrats?
-- can only be used for sessile and immobile species (eg. plants and slow-moving animals)
-- Some species can be counted to find their abundance but others that are very small or in high numbers require abundance to be calculated using percentage cover or frequency techniques
The frequency technique shows how common a species is but it does not give information on the estimated number of individuals or the size of the population
44
what is the technique for estimating population sizes of mobile animals?
The mark-release-capture method
45
what is the calculation for the mark-release-capture method?
N = (n1 × n2) ÷ m2
46
what do each of the letters in the mark-release-capture method calculation mean?
- N = population estimate
- n1 = number of marked individuals released
- n2 = number of individuals in the second sample (marked and unmarked)
- m2 = number of marked individuals in the second sample
47
outline the method to the mark-release-capture method
- The first large sample is taken. As many individuals as possible are caught, counted and marked in a way that won’t affect their survival e.g. if studying a species of beetle, a small amount of brightly coloured non-toxic paint can be applied to their carapace (shell)
- The marked individuals are returned to their habitat and allowed to randomly mix with the rest of the population
- When a sufficient amount of time has passed another large sample is captured
- The number of marked and unmarked individuals within the sample are counted
- The proportion of marked to unmarked individuals is used to calculate an estimate of the population size
48
what 4 assumptions have to be made when using the mark-release-capture method?
- The marked individuals are given sufficient time to disperse and mix back in fully with the main population
- The marking doesn't affect the survival rates of the marked individuals (e.g. doesn't make them more visible and therefore more likely to be predated)
- The marking remains visible throughout the sampling and doesn't rub off
- The population stays the same size during the study period (i.e. there are no significant changes in population size due to births, deaths or migrations into or out of the main population)
49
how can species richness be a misleading indicator of diversity?
it does not take into account the number of individuals of each species
50
which index takes into account both species richness and evenness?
Simpsons Index
51
what is the purpose of the Simpson index?
to quantify the biodiversity of an area
52
what do the N's in the Simpsons index stand for?
- n = total no. of organisms for a single species
- N = total no. of organisms for all species
53
how would you interpret the results of the Simpson index?
Values near 1 indicate high levels of biodiversity
Values near 0 indicate low levels of biodiversity
54
what does genetic diversity measure?
the genetic variation that exists within a species
55
how do individuals of the same species differ genetically?
Although individuals of the same species will have the same genes at the same loci they will not necessarily have the same alleles for each gene
56
where can genetic diversity be seen?
Between different populations of the same species
within a single population
57
why is diversity important?
it creates a larger gene pool which can help the population adapt, and survive changes in the environment
58
in which 3 ways can genetic diversity be assessed? what is the aim of all these?
- The proportion of polymorphic gene loci: Out of all the gene loci examined, what percentage show more than one allele
- The proportion of the population that is heterozygous for any specific gene locus: What fraction of individuals carry two different alleles at this locus?
- Allele richness: the number of different alleles present at a locus
59
what is a polymorphic loci?
loci that have two or more alleles
60
what is allele richness?
the number of different alleles present at a locus
61
how would you be able to tell when each different allele at a locus is being expressed?
- through the phenotype
- DNA sequences or the protein products of the alleles must be examined and compared
62
what is a monomorphic locus?
a locus that does not have multiple alleles
63
what the equation for calculating the proportion of polymorphic gene loci (P)?
P = number of polymorphic gene loci ÷ total number of loci investigated
64
what are the downsides of the (P) equation?
it does not illustrate the allele richness of a breed or species
65
Due to the limitations of P, what other methods can be used to assess genetic diversity
Comparing the amino acid sequences of proteins
Comparing DNA sequences
66
which humanfactors affect biodiversity?
Human population growth
Habitat destruction
Overexploitation
hunting
agriculture
Climate change
67
how does human population growth affect biodiversity?
- need more resources
- we take these which damages ecosystems
68
how does habitat destruction affect biodiversity?
- human needs = environments destroyed
- land clearance = Habitat loss + Habitat fragmentation
- deforestation
- destruction of marine habitats: coral reefs/sea beds
69
what is the result of habitat fragmentation/
populations living within these separated habitat fragments are more likely to suffer from inbreeding or local extinction)
70
how does over-exploitation affect biodiversity? give examples
- resources are being used up faster than they can be replaced - this is unsustainable
- e.g. fish stocks and trees
hunting is a form of over-exploitation
71
how does agriculture affect biodiversity? give examples
- monocultures of crops
- herbicides/pesticides - wash away in water + kill wildlife e.g. bees
- bigger fields needed
- hedgerow removal
72
what are two factors that make farming economically viable?
yield
profit
73
why is maintaining biodiversity not economically viable for farmers?
Farming practices that maintain or increase biodiversity can be expensive, labour intensive, time-intensive. They can also reduce the yield of crops and livestock e.g. more pests to eat crops, lowering the yield
74
how does climate change affect biodiversity? give examples
- causes more extreme weather events -> species dont have time to adapt to them
- global warming = more migration = species compete
- ocean acidification by CO2 = less calcium carbonate for shells
- Coral bleaching
75
what are the ecological reasons for maintaining biodiversity?
- A more diverse ecosystem is better able to survive and adapt to environmental changes or threats
- keystone species - When these species are lost there are several knock-on effects
76
what is a keystone species?
a species that has a disproportionate impact on an ecosystem
77
what are the economic reasons for maintaining biodiversity?
- Many of the medicines used today have originated from plants, fungi and bacteria
- Ecotourism
- Ecosystems have also made major contributions to the field of science and technology e.g. The specific enzyme used in DNA sequencing was first discovered in thermophilic bacterium
78
what are the aesthetic reasons for maintaining biodiversity?
- joy/pleasure for humans
- creative inspiration
79
what are the social reasons for maintaining biodiversity?
- activities to be done socially in nature e.g. birdwatching, walking, climbing
80
what are the moral reasons for maintaining biodiversity?
humans have no right to cause the extinction of other species
81
what are the environmental reasons for maintaining biodiversity?
- Plants absorb carbon dioxide from the atmosphere + reduce greenhouse effect
- Microorganisms digest and break down the masses of organic waste
- drinking water comes from the role of plant transpiration in the water cycle
- plants as producers- energy sources
82
what are the agricultural reasons for maintaining biodiversity?
- wild relatives of crops can provide a source of genetic diversity to rescue crops that are affected by disease or other disasters - genetic reserve
- insects as pollinators
83
what are the two types of conservation?
- in situ - kept in their natural habitat
- ex situ - taken out of natural habitat
84
what are 5 conservation methods?
- zoos
- marine parks
- national parks
- botanic gardens
- seed banks
85
what is an endangered species?
a species that is being threatened with extinction
86
what are the in situ conservation methods?
- national parks/wildlife reserves
- marine parks
87
what are the ex situ conservation methods?
zoos
botanic gardens
seed banks
88
what restrictions are in place in national parks?
-- Humans access is strictly controlled
-- Industrial activities such as agriculture and building are tightly regulated
-- Hunting is limited or completely prohibited
89
what restrictions are in place in national parks?
restrictions to prevent overfishing and pollution
90
why is public engagement important for the long term success of conservation efforts?
-- National and Marine parks can attract thousands of tourists each year which increases money and awareness for the conservation effort
-- Involving members of the local community in the management of protected areas can provide jobs and increase acceptance of the parks
-- Some of the profits made from parks can be used to improve the health and education standards in the nearby communities to illustrate the benefits of having such areas nearby
91
what are the benefits of captive breeding programmes?
can preserve endangered species
species can be gradually reintroduced
can import breeding material
provide animals with:
- food
- shelter
- absence of predators
92
what are the downsides of captive breeding programmes?
- inbreeding -> limited breeding parters
- organisms may not be able to be reintroduced into the wild
93
what are the benefits of in situ conservation?
- preserves interdependent relationships in a habitat
94
what active management techniques are in place in a wildlife reserve?
- controlled grazing
- restricted human access
- controlled poaching
- feeding animals
- reintroduction of species
- culling/removal of invasive species
- halting succession
95
how are marine conservation zones beneficial?
- create areas of refuge
- ban fishermen
96
what are the downsides or marine conservation zones?
often need very large area
animals often migrate e.g. for breeding
97
how are botanic gardens beneficial?
provide the right/best resources for the species to grow:
- watering
- soil nutrients
- removal or prevention of pests
98
describe seed banks
- seeds preserved by freezing at -20 degrees to retain viability: the speed at which they germinate is slowed down
- a store of genetic material
99
what is a downside of seed banks?
don't work for all plants -> tropical rainforest seeds die when dried out
100
how can inbreeding in captive breeding programmes be prevented?
- keeping international catalogues of genealogical data
101
why might some organisms bred in captive breeding programmes be unable to be reintroduced into the wild?
- loss os disease resistance
- may not have learnt survival behaviours e.g. foraging for food
- may be too genetically different to breed
- habitat may be too small - causes tensions e.g. limited food/territory
102
what are our 4 conservation agreements?
- The International Union for the Conservation of Nature (IUCN)
- The Convention on Biological Diversity (CBD)
- The Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES)
- The Countryside Stewardship Scheme (CSS)
103
what does IUCN stand for?
The International Union for the Conservation of Nature
104
what does CBD stand for?
The Convention on Biological Diversity
105
what does CITES stand for?
The Convention on International Trade in Endangered Species of Wild Flora and Fauna
106
what does CSS stand for?
The Countryside Stewardship Scheme
107
what does the IUCN do?
- classifies organisms based off their population numbers and the threats and risks
- assesses the conservation status of animal and plant species around the world
108
what does the CBD do?
- The conservation of biological diversity by use of a variety of different conservation methods
- The sustainable use of biological resources
- The fair and equitable sharing of benefits arising from genetic resources
agreed to design and implement national strategies for conservation + sustainability
109
what does CITES do?
- aim is to control the trade of endangered species and their associated products
- organisms are categorised into 3 categories, each of which have different trading laws
110
what does CSS do?
- provided funding (i.e. a financial incentive) to farmers and private landowners in England who used environmental management strategies to protect and increase the natural biodiversity on their land
111
what are 5 strategies that farmers in the CSS can implement?
- Provide and protect valuable wildlife habitats such as ponds, hedgerows and buffer zones surrounding farmed areas
- Ensure their land is managed well, maintaining its traditional character
- Protect any natural resources or historic features present on their land
- Conserve any traditional crops or livestock present on their land
- Provide visitor opportunities so people can learn about the countryside and how important it is in sustaining biodiversity
BIOLOGY
flashcards
Decks in class (38)
# Cards
-
Eukaryotic plant cells6
-
monomers, polymers and elements4
-
Prokaryotic cells8
-
Eukaryotic Cells22
-
Biological molecules7
-
STAGES IN PREPREPARED SLIDES4
-
MODULE 2 - MICROSCOPES AND STAINING40
-
MODULE 2 - CELL COMPONENTS24
-
MODULE 2 - WATER10
-
MODULE 2 - CARBOHYDRATES AND LIPIDS33
-
MODULE 2 CHEMICAL TESTS8
-
MODULE 2 - PROTEINS31
-
MODULE 2 - ENZYMES26
-
MODULE 2 - BIOLOGICAL MEMBRANES24
-
MODULE 2 - NUCLEOTIDES AND NUCLEIC ACIDS25
-
MODULE 3 - LUNG VOLUMES7
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MODULE 3 - PARTS OF A SPIROMETER6
-
MODULE 3 - EXCHANGE SURFACES59
-
MODULE 3 - TRANSPORT IN ANIMALS120
-
MODULE 3 - TRANSPORT IN PLANTS55
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MODULE 4 COMMUNICABLE DISEASES158
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MODULE 4 - BIODIVERSITY111
-
MODULE 4 - classification and evolution109
-
MODULE 5 - Neuronal communication135
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MODULE 5 - Hormonal communication definitions6
-
MODULE 5 - homeostasis21
-
MODULE 5 - the liver and kidney106
-
MODULE 5 - The adrenal glands52
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MODULE 5 - plant responses40
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MODULE 5 - Photosynthesis119
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MODULE 5 - RESPIRATION137
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MODULE 6 - Cellular control - body plans40
-
MODULE 6 - controlling gene expression36
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MODULE 6 - Patterns of inheritance and manipulating genomes176
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MODULE 6 - Genome sequencing and DNA profiling11
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MODULE 6 - cloning and biotechnology184
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MODULE 6 - ECOSYSTEMS + POPULATIONS AND SUSTAINABILITY212
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exam style questions103
