biodiversity Flashcards
what are some economic reasons for maintaining biodiveristy
- organisms can provide valuable ecosystem services eg. cleaning water and pollination of crops which reduces money spent on doing this artificially
- areas rich in biodiversity attract tourists which provides job opportunities.
- some plants are a source of medicines eg. digitalis origionated from foxglove which are sold on a global scale
- genetic recourses are useful and allow us to adapt to changes
eg. alleles in a plant for drought resistence can be isolated and used to genetically engineer a drought resistent crop.
what are some ecological reasons for maintaining biodiversity
- preserving existence of keystone species is important, if they were to go extinct this would have a large impact on ecosystem and food chains.
maintain a global gene pool - invaluable genetic recourse, vital in species so they can evolve and adapt to new predators, diseases and environmental changes. eg. alleles for disease resistance
what is monoculture, what are some disadvantages of monoculture
the production of a single species of plant.
In monoculture, plants are often genetically identical. This can therefore result in an ideal situation for pests, weeds and plant diseases to emerge. If they can outcompete or affect one plant, they can do so for all the other identical plants.
+ depletes the soil of particular mineral ions
what are the 2 types of conservation
in situ - protecting species in their natural habitat
ex situ - removing part of the population from threatened habitat and placing in new location. Eg zoo’s
what are the 4 types of variation
intraspecific - variation within same species
interspecific - variation between different species
continuous variation - when individuals in a population vary within a range. No distinct categories eg. height, mass, width
discontinuous variation - two or more distinct categories, each individual fits into only one category, no overlap
how is continuous data represented
line graphs and histograms.
how is disconintuous data represented
bar chart
what is the cause of variation
different species have different genes
individuals of the same species have the same genes but different alleles. Alleles code for genotype, differences in genotype result in variation of phenotype.
environmental factors such as climate and food can cause variation
genetics determines the characteristics an organism is born with, but environmental factors can influence how these characteristics develop
what causes genetic variation
- mutation
- random mating between organisms
- random fertilization
- crossing over (or recombination) between chromatids of homologous chromosomes during meiosis
why is genetic variation/diversity important
Genetic variation is essential for natural selection because natural selection can only increase or decrease frequency of alleles that already exist in the population.
Genetic variation is advantageous to a population because it enables some individuals to adapt to the environment while maintaining the survival of the population.
what is genetic diversity
how many genes and gene pools there are in a population. Looks at the number of loci and compares to the number of alleles.
For example, a population with many different alleles at a single chromosome locus has a high amount of genetic variation
what are the 3 types of diversity
habitat diversity
species diversity - species richness and species evenness
genetic diversity - variation of alleles within a population of a species
what is biodiversity
the variety of living organisms in an area
what are the 4 types of sampling that can be done to assess biodiversity
random
opportunistic
stratified
systematic
what is random sampling
dividing area into grid using measuring tapes,
uses a random number generator for co-ordinates
placing a quadrat at those co-ordinates and sampling abundance
what is a strength and limitation of random sampling
strength - avoids bias
limitation - may underestimate diversity if not all areas/types of habitat are sampled therefore data may not be representative
what is stratified sampling
dividing up the area into distinct zones/habitats then sampling the area according to the ratio of areas.
what is a strength of stratified sampling
ensures all areas are sampled so prevents small populations from being missed out
allows areas of different population levels in the same habitat to be sampled equally
what is a limitation of stratified sampling
may lead to over-representation of some areas, for example small areas may be sampled more than necessary because they look different from other areas.
what is opportunistic sampling
areas are chosen to be sampled based on prior knowledge of the habitat or choosing areas that are of interest.
what is a strength and limitation of opportunistic sampling
easier and quicker
subject to bias, for example species that are more noticable may be sampled more than unnoticable species leading to an inaccurate estimate of biodiversity
what is sytematic sampling
samples are taken at set regular intervals along the transect
what is a strength and limitation of systematic sampling
this is useful to view a change in biodiversity or populations along a distance
method has the risk of missing species as only a small area is sampled, could result in underestimation of diversity.
what is species richness
number of different species in an area
what is species eveness
measure of the relative abundance of each species in an area
how is genetic diversity maintained in zoos
breeding programmes are managed to increase GD
databases are kept up to date and it is decided which animals should be paired for breeding and these animals can be transferred between zoos. this reduces interbreeding.
what is polymorphism
described a loci (position on a gene) that contains 2 or more alleles.
how can genetic diversity be calculated
by assessing the proportion of polymorphic. gene loci in a population
prop. of polymorphic loci = no. of polymorphic loci / total number of loci
what might in situ conservation involve
establishing protected areas, creating national parks and restricting urban development.
controlling/preventing introduction of species that threaten local biodiversity.
protecting habitats, controlling water levels, trimming trees, restoring damaged areas
what are some strengths and limtations of in situ conservation
conserves the species and their natural habitat, less disruptive to the species and allows larger populations to be protected.
however cannot control all factors such as climate change and predators
what might ex situ conservation involve
relocating a number of the population to a different area.
breeding programmes and release into wild
botanic gardens - seeds. can be frozen and stored their fertility is maintained - useful if natural reserves are destroyed.
what are some strengths and limitations of ex situ conservation
protects individual animals in a controlled environment, allowing predation and hunting to be more easily controlled. Competition for recourses can be controlled and is easy to check on health and treat diseases
breeding can be manipulated
- only a small number of population can be. cared for
difficult and expensive to sustain right environment conditions
animals used to human contact more likley to catch disease
some species do not adapt to new environment
what is a keystone species
one that has a profound effect on the ecosystem in which they live, especially on the other trophic levels. Keystone species play such a vital role in ecosystems that the entire ecosystem may collapse in their absence. Many, but not all, keystone species are apex predators.
what was the aim of the rio convention on biological diversity and what was the result
was an international agreement that aimed to develop international strategies on conservation of biodiversity and how to use recourses in a sustainable way.
resulted in international laws that recognised conserving biodiveristy is everyone’s responsibility.
what was the aim of the CITES agreement and what was the outcome
aimed to increase international cooperation in regulating trade of wild animals and plant species.
made it illegal to trade in products made from endangered species
what was the aim of the countryside stewardship scheme and what was the outcome
aimed to conserve wildlife and biodiver and to improve and expand habitats by promoting specific managment techniques to land owners.
Government offered 10 year agreement to pay farmers who followed managment techniques such as regenerating hedgerows.
