Biodiversity Flashcards
define biodiversity
the variety of living organisms in an area
what factors are considered in biodiversity
habitat diversity, species diversity, genetic diversity (variety of alleles)
what is a habitat
an area inhabited by a species
what is a species
group of similar organisms able to reproduce to give fertile offspring
what are three types of non random sampling and explain how they’re carried out
systematic sampling- samples taken often at intervals, along a line
opportunistic sampling- when samples are chosen by the investigator, data will be biased
stratified sampling- when different areas in a habitat are identified an sampled separately in proportion to their part of the habitat as a whole
how would you know that results in a sample aren’t juts due to chance
analyse results statistically
what is species richness
the number of different species in an area
what is species evenness
a measure of the relative abundance of each species in an area
how would you measure species diversity
Simpson’s Index of Diversity
what does n, N and E represent in Simpson’s Index of Diversity
n= total number of organisms in one species
N= total number of all organisms
E= sum of
what is polymorphism
a locus that has two or more alleles
how do you calculate the proportion of polymorphic gene loci in a population
number of polymorphic gene loci/ total number of loci
what effect has human population growth had on biodiversity
habitat loss
over-exploitation
urbanisation
pollution
what effect does monoculture have on biodiversity
habitat loss as land is cleared to make way for large fields
los of local plants and animals
loss of heritage varieties as they don’t make enough money so are not planted any more
what are the ecological reasons for maintaining biodiversity
ecosystems are interdependent so they depend on each other to survive
disruption of food chains
disruption of nutrients cycle
what are keystone species
species that many other species in an ecosystem rely on often predators with a relatively low population
why do genetic resources need to be maintained
provide everyday products e.g food and drink
allow adaptations to changes in the environment
what are economic reasons to maintain biodiversity
continuous monoculture causes soil depletion as nutrients are used up so more money is spent on fertilisers and yield decreases
what are the aesthetic reasons for maintaining biodiversity
attractive landscapes, can attract more visitors
what is in-situ conservation and give a few examples
protecting species in their natural habitat
establishing protected areas like national parks
restoring damaged areas
what are some advantages and disadvantages of in situ conservation
often both the species and habitat are conserved
, less disruptive, large populations can be protected
can be difficult to control things threatening a species e.g climate change
chances of population recovering are greater with ex-situ
what is ex-situ conservation and give some examples
protecting species by removing part of the population from a threatened habitat
relocating organsims
breeding organisms in captivity then releasing them into the wild
seed banks
what are the advantages and disadvantages of ex situ conservation
competition for resources is reduced
health checks
individual animals can be controlled
breeding canoe controlled
can be used to reintroduce species that have left an area
only a small number of individuals can be cared for
can be expensive
species can’t breed successfully in captivity
what is the Rio Convention on Biological Diversity
international agreement that aims to develop international strategies on the conservation of biodiversity and how to use animal and plant resources in a sustainable way
what is the CITES agreement
designed to increase international cooperation in regulating trade in wild animal and plant specimens, made it illegal to kill endangered species
What is the Countryside Stewardship scheme
conserve wildlife and biodiversity and to improve and extend wildlife habitats by promoting specific management techniques to landowners
