deck_13003253 Flashcards
What is a species?
a group of individual organisms with similar characteristics that can breed to produce fertile offspring
What is a habitat?
the natural home or environment of a species
What is biodiversity?
the variety of organisms/species present in an area
What are the types of biodiversity?
Genetic
Habitat
Species
Describe genetic biodiversity?
Variety of genes found in individuals in a species
Describe habitat biodiversity
the range of habitats in an area
Describe species biodiversity
species richness: # of species in an area
species evenness: number of individuals within a species in an area
Define population
all the organisms of a particular species found in an ecosystem
Define community
Populations of all species found in a particular ecosystem
Define ecosystem
system of organisms interacting with each other and the environment
Define abiotic/biotic
abiotic: non-living components (environmental)
biotic: living components
Define sampling
measurement of abundance and distribution of species in an area
Define random sampling
non-biased way of sampling where every individual has an equal likelihood of selection
allows estimation of population
Why is it important for samples to be random?
removes bias therefore making sample more reliable
What are the 3 types of non-random sampling?
Opportunistic
Stratified
Systematic
Describe stratified sampling
dividing populations into strata (sub-groups) based on characteristics
eg. male and female
Describe systematic sampling
used when there is a clear change in different areas of habitat using a line/belt transect
Describe opportunistic sampling
selecting organisms that are conveniently available to the experimenter
Describe kick-sampling
disturbing substrate in river banks to release organisms where they are captured downstream
Describe sweep netting
sweeping a net in long wild grass to catch flying invertebrates
Describe pitfall traps
a hole in soil deep to catch vertebrates covered to stop rainwater entering
Describe tree-beating
laying large cloth out and beating a tree to knock organisms and catch them in the cloth
Describe a pooter
glass container used to suck small organisms - filter covers one tube to stop organisms being sucked into mouth
Describe species evenness
the number of organisms within a species in an area
Describe species richness
the number of species present in an area
What are genetic causes for loss/gain of biodiversity?
+ mutations
+ interbreeding
- selective breeding
- captive breeding
- cloning
- genetic drift
- natural selection
- genetic bottleneck (catastrophic event)
Define abiotic factors
non-living components of an ecosystem
- temperature
- pH
- humidity
- light
- water
What is a frame quadrat?
square frame divided into a grid
- type and number of each species sampled
What is a point quadrat?
frame containing horizontal bar - pins stick through the bar
- each species the pin touches is recorded
What is a polymorphic allele?
gene with more than two possible alleles
Define Locus
position of gene on a chromosome
Why are seed banks effective in maintaining biodiversity?
- seeds can be easily transported and stored
- prevents extinction
- preserves genetic material
When would random sampling be appropriate?
when the population size is small or the size of the individual samples and their number are relatively small
When would using systematic sampling be appropriate?
when a habitat is non-uniform and gradual changes occur
Explain why greater genetic biodiversity increases a species’ chances for long-term survival
- greater genetic biodiversity = more likely to adapt to environmental changes
- some organisms likely to carry advantageous allele - carries through offspring
Explain why it may not be possible to release some captively bred organisms back into the wild
- no resistance to diseases
- some behaviour is learned (eg. hunting)
- habitats need to be reintroduced
Explain what measuring species diversity tells us about the stability of an ecosystem
- diversity often proportional to stability of ecosystem
- so more stable = evenly distributed species
Explain why the use of data loggers and sensors is advantageous.
- reduces human error
- detects rapid changes
- high degree of precision
Name 3 issues that affect biodiversity that are due to human population size
- deforestation
- climate change
- agriculture
Describe deforestation
permanent removal of large woodlands for housing, fuel and to create space
Name two ways in which genetic biodiversity of a population can be increased.
- mutation of DNA creating new alleles
- interbreeding between populations transfer alleles
What 4 ways can deforestation affect biodiversity?
- can occur naturally
- if only specific tree cut - species diversity reduced
- habitat destruction reduces number of animal species present (food and shelter destroyed)
- animals forced to migrate - biodiversity of other areas increases
Name 5 methods associated with agriculture that affect biodiversity.
- removal of hedgerows
- pesticides - reduce species diversity
- herbicides
- monoculture
- deforestation
Describe monoculture and its impacts on biodiversity
- producing only one crop lowers biodiversity directly
- few animal species will be supported by one type of plant
Describe 3 aesthetic reasons for maintaining biodiversity
- presence of plants and animals enriches our lives
- inspiration for musicians and artists
- patients recover more rapidly from stress when supported by plants and natural environment
What are 3 reasons for maintaining biodiversity
- aesthetic
- economic
- ecological
Describe 8 economic reasons for maintaining biodiversity
- soil erosion and desertification reduces ability to grow crops - resource dependence on other nations
- non-sustainable removal of resources will lead to collapse of industry in area
- species with potential economic importance may become extinct before being discovered
- continuous monoculture = soil depletion (red. in soil biodiversity) same land is reused - farmer reliant on expensive chemicals to maintain productivity
- high biodiversity protects from abiotic stress and disease - change in conditions can destroy entire crops (irish famine)
- high biodiversity = more tourism
- greater diversity = potential to manufacture new products in future
- plant varieties needed for cross-breeding = better characteristics
Describe 2 ecological reasons for maintaining biodiversity
- organisms interdependent - removal of one species has knock-on effect
- removal of keystone species - ecosystem drastically changed and becomes unstable
Define the term ‘keystone species’ and why it is important
keystone species: key role in maintaining structure of ecological community
- disproportionally large effect on environment compared to their abundance
How is Simpson’s Index of Biodiversity calculated?
D = 1 - sum of (total # organisms in species/total number of species)^2
What is the formula for genetic biodiversity?
proportion of polymorphic gene loci = # polymorphic gene loci / total # loci
What are the implications of a habitat having high biodiversity?
- large # of successful species
- wide range of adaptions to environment
- complex food webs
- small effects when environment changes
What are the implications of a habitat with a low biodiversity?
- few successful species
- specific adaptions to environment
- simple food webs
- major effects when environment changes
Why is it important to monitor genetic biodiversity?
to monitor health of population and ensure long term survival
Define in-situ conservation
conservation within natural habitat
Define ex-situ conservation
conservation out of natural habitat
Name 2 methods of in situ conservation
- wildlife reserves
- marine conservation zones
Name 3 methods of ex situ conservation
- botanic gardens
- seed banks
- captive breeding programmes
Describe the role of botanic gardens in maintaining biodiversity.
species are actively managed & provided with resources to grow (soil nutrients, watering, removal of pests)
Describe the role of seed banks in maintaining biodiversity.
seeds stored so that new plants can be grown in the future - extinction prevented
- easy to transport
- stored easily
Explain how seed banks store the seeds and why these methods are important.
- seeds are dried and stored at temperatures of -20C
- slows rate at which they lose ability to germinate
Describe how captive breeding programmes reduce genetic biodiveristy.
- small number of captive individuals available for breeding
- there is no gene flow
Explain the aim of captive breeding programmes in maintaining genetic biodiversity.
aim to create a stable, healthy population of a species and gradually reintroduce it back to natural habitat
Describe 7 methods of active management in wildlife reserves.
- controlling grazing - only for certain amount of time, allowing area of land species to recover
- restricting human access - providing paths so plants aren’t trampled
- controlling poaching
- feeding animals - ensure more organisms survive to reproductive age
- reintroduction of species - adding species to areas that have become locally extinct
- culling or removal of invasive species - removal of competition for native species
- halting succession - only way of preventing areas such as moorland from becoming woodland is grazing
Describe the role of marine conservation zones in maintaining biodiversity.
creates areas of refuge from which populations can build up and repopulate areas
Describe 3 ways in which zoos can contribute to conservation.
- provide animals shelter, abundant supply of food, absence of predators and vet treatment
- genealogical data is kept on individuals so when bred, they choose the pairs that will maximise genetic biodiversity
- money earned can be used as funding for researching new methods of conservation
State the full name of CITES and explain how it helps protect biodiversity.
Convention on International Trade in Endangered Species
- regulates international trade of wild plant and animal specimens and their products
- protects species from over-exploitation that could endanger them
State 3 outcomes from the Rio convention.
Convention on Biological Diversity (CBD)
- requires countries to develop national strategies for sustainable development
- agreement to stabilise greenhouse gas concentration in atmosphere
- prevent transformation of fertile land into desert
What does conservation mean?
maintenance of biodiversity through human action/management - managing ecosystems so resources can be used without running out
