1
Q
How can mutations affect biodiversity?
A
- occur in DNA and creates newallele
2
Q
Interbreeding
A
- individuals from two populations breed and transfer alleles
- causes gene flow
3
Q
Selective breeding
A
- few individuals in population selected for their advantageous characteristics and bred
4
Q
How does natural selection affect biodiversity
A
- species evolve to code for characteristics that code for advantageous characteristics
- less advantageous genes will be lost overtime
5
Q
Factors that affect genetic biodiversity (7)
A
- Mutations in DNA
- Interbreeding; gene flow
- selective breeding
I - artifices cloning
- natural selection
- founder effect
- genetic drift
6
Q
Importance of biodiversity
A
- Maintains balanced ecosystem as all species are dependant
7
Q
Human activity that affects biodiversity (3)
A
- Deforestation
- Agriculture: increases monoculture
- Clearing land for housing
- Climate change; human activity increases global warming
8
Q
Sampling and its uses (3)
A
- Taking measurements of a limited number of individual organisms present in a particular area
- measures particular characteristics and abundance of species
- helps make predictions or generalisations
9
Q
Random sampling
A
- Selecting individuals by chance, each individual in the population has an equal chance of being selected
10
Q
Non-random sampling
A
- Opportunistic; organisms conveniently available
- Systematic; sampling different areas within an overall habitat. Measures change over an area eg transect
11
Q
What can affect reliability of a sample
A
- Sampling bias
- Chance; organism might not be representative
12
Q
Different sampling techniques for animals
A
- Pooter: small insects
- Sweeter nets: organisms in long nets
- Pitfall traps: small invertebrates and mammals
- Tree beating
- Kick sampling: river bank and bed
13
Q
Sampling for animals
A
- Quadrat; frame or point
14
Q
Species evenness (2)
A
- Number of individual species on a given area
- How close the number of species are
15
Q
Why are abiotic sensors used? (4)
A
- Human errors
- greater precision
- data can be stored and tracked on computer
- rapid changes can be detected
16
Q
What are abiotic factors; included examples(6)
A
- Nonliving conditions in an environment. Usually have direct affect on organisms in habitat.
- eg; pH, wind speed, light intensity, relative humidity, temperature
17
Q
How is biodiversity calculated
A
- Simpson’s index; takes into account richness and evenness with 1 being the highest diversity
18
Q
Habitat features for low biodiversity (5)
A
- few numbers of successful species
- stress/ extreme with few ecological niches
- simple food webs
- very specific adaptations
- change to the environment massively affects ecosystem
19
Q
Importance of generic biodiversity
A
- The more alleles present in a population, the more biodiversity
- Species with greater genetic biodiversity are more likely to be able to adapt to environment
- It is more likely for organisms to contain advantageous characteristics
20
Q
Polymorphism (2)
A
- Genes that have more than one allele
- eg blood type in humans are determined by 3 alleles
21
Q
How does deforestation affect biodiversity (3)
A
- Reduces number of trees
- destroys animal habitat so reduces animal species present in that area
- animals forced to migrate to other areas which increases neighbouring biodiversity
22
Q
How does agriculture affect biodiversity
A
- Pesticides reduces biodiversity
- herbicides also reduces biodiversity
- Monoculture
23
Q
Reasons for maintaining biodiversity
A
- Aesthetics; how the region appears
- Economical; how the region can affect income
- Ecological reasons; how species are supported in the region
24
Q
Economic reasons for maintaining biodiversity (7)
A
- Soil erosion and desertification due to deforestation causes lack of crops and decline in resources
- By not conserving organisms used to make things, the removal of resources makes economical industries viable
- Species with potentially economical importance can become extinct through large scale habitat loss
- Monoculture; soil depletion makes soil weaker and plants more susceptible to pests
- Lack of biodiversity makes organisms more vulnerable against abiotic stresses eg disease/ weather
- Promotes tourism with pleasing biodiversity
- Plant biodiversity means advantageous characteristics can be interbred
25
Ecological reasons for maintaining biodiversity?
- All organisms are dependant on each other for survival
- Removal of keystone species drastically affects the whole ecosystem. Important to protect keystone species as they have largest biomass and productivity
- Allows regulation of oxygen and CO2 in the atmosphere.
- Allows minerals to be recycled in the ecosystem.
26
What is conservation
- Preservation and management of environment of natural resources.
- In situ; within natural habitat
- ex situ; out of natural habitat
27
How are species classified in terms of classification (4)
- Extinct
- Extinct in the wild; only exists in captivity
- Endangered; danger of extinction
- Vulnerable; considered likely to become endangered in the near future
28
In situ conservation
- preserves interdependent relationships present in a habitat so interlinked species are also preserved
- Wildlife reserves
- Marine conservation zones
29
Describe wildlife reserves techniques (6)
- Controlled grazing
- restricting human access
- controlled poaching
- feeding animals
- reintroducing species
- removing invasive species
30
Ex situ conservation techniques (3)
- Botanic gardens
- Seed banks
- captive breeding
31
Marine conservation zones (2)
- Creates areas of refuge within populations can build up and repopulate
- large areas are targeted which allows target species to move over large distances
32
Botanic gardens (2)
- Species are given best resources: soil nutrients, watering, prevention of pests
- plants grown are a potentiometer source of genes that have resistance to disease, pests and parasites
33
Seed banks (3)
- Gene bank: provides back up against extinction of wild plants
- seeds collected and dried below 20 degrees: Slowly down the rate of seed germination
- does not work on all plants: tropical rainforest trees
34
Captive breeding programmes (3)
- Producing offsprings of species in human controlled environment
- Includes zoo, aquatic centres
- the species are eventually released back to its natural habitat after producing a healthy population of species
35
Why may some species in captive breeding not be able to be released? (4)
- Disease: may have not developed resistance to new diseases
- Behaviour: species have learned behaviour which are not beneficial- eg looking for food.
- Genetic races: captive animals become so different that they cannot interbreed with original population
- Habitat; natural habitat must be stable and restored before animal is reintroduced
36
Conservation agreements
- cross boarder protection
- International Union for the Conservation of Nature
- The Rio Convention
- Countryside stewardship scheme
37
International Union for the Conservation of Nature (IUCN) (3)
- Red List is published each year which details conservation status of threatened animals
- Countries work together to conserve the species
- Establishes the Convention on International Trade in Endangered Species (CITES): trade in wild animals and plants across boarders
38
The Rio Convention (6)
- The Convention on Biological diversity (CBD): countries have to develop national strategies for sustainable use of organisms
- share genetic resources
- share access to scientific knowledge
- promote ex situ conservation; eg set up seed banks
- raise awareness of biodiversity to general public
- allow cohesive international cooperation
39
Countryside stewardship scheme/ Environmental Stewardship scheme (5)
- Payments offered to farmers and land managers to enhance and conserve English landscape
- Sustains beauty and biodiversity
- restores neglected land
- conserves archaeological and historic features
- improves and creates wildlife habitats
40
What are the different ways of improving sampling techniques (3)
- Seasonal variation; different times of the year and day
- Methods to ensuring individuals are not counted again
- Efficient ways of capturing species and correctly identifying them
41
Advantages of seed banks over Adult plants
- take up less space
- rate of germination is slowed down and can be stored for a longer period
- stores greater genetic diversity
- easier to transport
42
CITES (5)
- Conservation on International Trade of Endangered Species
- Monitors trade in endangered species
- Ensures trade does not endanger wild populations
- Prohibits trade in wild plants
- allows trade in less endanger organisms
43
What does a high value in Simpson's Index of diversity indicate? (4)
The habitat has a high biodiversity.
There is a high number of species which are represented evenly.
Habitat is stable and resistant to disruption.
Habitat is worth conserving.
44
What does a low value in Simpson's Index of diversity indicate? (4)
Habitat has a low bioversity.
Habitat is dominated by one/ a few species.
Habitat is unstable and susceptible to disruption.
Habitat may be man made.
Biology, Module 4 OCR
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