biodiversity Flashcards
3 strands of biodiversity?
ecosystem diversity
species diversity
genetic diversity
species that lack genetic diversity due to isolation/ low population numbers are much more vulnerable to fluctuations due to what 3 factors?
climate change
disease
habitat fragmentation/ destruction
coral within coral reefs provides what to the organisms within the ecosystem?
microhabitats
shelters
bacteria/microorganisms
breeding grounds/ nesting sites
what is a keystone organism?
has a disproportionate effect on other species
many other organisms depend on it for they survival
when was the rio convention on biological diversity?
what else is it referred to as?
1992
earth summit
on what 3 levels does the rio convention on biological diversity consider biodiversity?
1) the range of habitats/ microhabitats within an ecosystem
2)the range of species within each ecosystem
3)the range of genes/alleles within each species
what does the rio CBD encourage?
cooperation between countries and states
encourages each partner to develop a national strategy for conservation and the sustainable use of biological diversity
states that partner states must adopt e situ measure to compliment in situ measures
what is ex situ and in situ conservation
ex situ= out of natural habitat
in situ= in natural habitat
circle of CBD?
conservation of biological diversity
sustainable use of biological diversity
fair and equitable sharing of benefits arising from the utilisation of biological diversity
what is meant by ‘variation’
differences due to genes and the environment
what are the 2 types of variation?
intraspecific variation=differences within a species
interspecific variation= differences between species
population definition
members of the same species living in a habitat
ecosystem definition
all members of all species and their environment (abiotic factors)
species definition
a group of organisms which can interbreed to produce fertile offspring
what are the 3 levels of biodiversity?
ecosystem/habitat biodiversity
species biodiversity
genetic biodiversity
describe ecosystem/habitat biodiversity
the variety of ecosystems in an area OR the variety of habitats within an ecosystem
the higher the ecosystem diversity, the more stable it is and the less likely it is to change
describe species biodiversity
the variety of species within an ecosystem
considered on 2 levels: species richness and species evenness
definition of species richness
the number of different species in an ecosystem
species evenness definition
the relative abundance of each species
disadvantage of lower species evenness
much less stable
more susceptible to chnage
describe genetic biodiversity
the variety of genes in a gene pool for a particular species
(each gene could have multiple alleles, which increases variation in offspring. combination of meiosis (crossing over/ independent assortment) and random fertilisation increasing number of combination of alleles within a population i.e. increasing genetic diversity)
what are phenotypic differences due to?
a combination of genes and environment
gene definition
a sequence of DNA bases that codes for a specific amino acid sequence
do members of the same species have the same or different genes?
they have the same genes but different versions of them (ALLELES)
what is genetic diversity determined by?
the variety and frequency of different alleles in a population
methods used to calculate genetic diversity?
proportion of polymorphic genes
proportion of heterozygous genes
proportion of genes that are homozygous recessive
what is a polymorphic gene?
a gene that has more than 2 possible alleles
what is a heterozygous geen
a gene that has dominant and recessive alleles expressed
proportion of polymorphic genes equation
no. of polymorphic genes
/////////////////////////////////
no. of genes studied
habitat definition
the specific place where an organism lives
which measure of biodiversity is most significant when assessing the health of one ecosystem
species diversity: an ecosystem, containing multiple habitats, should support multiple different species
how can a habitat contain many species but have a low biodiversity?
high species richness
low species evenness
global biodiversity is in decline
explain how human population growth, agriculture and climate change contributes to a decline in biodiversity
HUMAN POP GROWH
need for more agricultural land/ housing
destroys habitats
more waste produced
more pollution produced
damaging ecosystems
specific example (e.g. overfishing)
global biodiversity is in decline
explain how human population growth, agriculture and climate change contributes to a decline in biodiversity
AGRICULTURE
agricultural land has monoculture/lower biodiversity
loss of older/wild type strains
reduced genetic diversity
subject to disease
inability to adapt to changing conditions
altering habitats
specific example (e.g. draining wetlands reduces habitat diversity)
pesticide use
use of fertiliser
nitrate pollution
eutrophication