Biodiversity Flashcards
biodiversity definition
the variety of living organisms in an area
species definition
a group of similar organisms that can reproduce to produce fertile offspring
habitat definition
the area that a species lives in
what are the 3 types of biodiversity?
habitat diversity
species diversity
genetic diversity
what can species diversity be further divided into?
species richness and species evenness (the relative abundance of each species in an area)
which stat test measures diversity?
Simpson’s index of diversity
what is n in Simpsons index of diversity?
the total number of individuals of one species
what is N in Simpsons index of diversity?
the total number of organisms of all species
what is used to measure genetic diversity?
genetic polymorphism (calculating the proportion of polymorphic gene loci)
what is polymorphism?
when a gene loci has two or more alleles
what is an example of genetic biodiversity?
different breeds within a species (e.g. dog breeds)
what are the 3 types of non-random sampling?
opportunistic
stratified
systematic
the 4 sampling techniques we need to know
pitfall traps
pooters
quadrats
sweep nets
what is the value for Simpsons index of diversity always between and what does this mean?
0 and 1
0 = least diverse
1 = most diverse
what is an example of a population in which the genetic diversity may be low?
an isolated population e.g. bred in captivity (zoos), rare breeds and pedigree animals
what are the 3 factors affecting biodiversity
human population growth
agriculture (monoculture)
climate change
why is human population growth decreasing global biodiversity?
urbanisation
habitat loss
pollution
over-exploitation of resources
what is monoculture?
the growing of a single variety of a single crop
what are the 3 key reasons for maintaining biodiversity?
ecological reasons
ethical reasons
aesthetic reasons
why is it important to maintain biodiversity for ecological reasons?
to protect keystone species and to maintain genetic resources (for food, drink, clothes, drugs etc.)
what is a keystone species?
a species that has a disproportionate effect on its environment relative to its abundance
why is it important to maintain biodiversity for economic reasons?
to reduce soil depletion (caused by continuous monoculture) because this leads to increased spending on fertilisers
2 examples of in-situ conservation
marine conservation zones
wildlife reserves
3 examples of ex-situ conservation
botanic gardens
seed banks
zoos
which is often more successful in-situ or ex-situ conservation?
in-situ
advantages and disadvantages of in-situ conservation
advantages
- keep species in natural habitat (less disruptive)
- more successful than ex-situ
- larger populations can be protected
disadvantages
- its difficult to control some factors e.g. predators, poaching, disease
the 3 conservation agreements we have to know
CITES - convention on international trade in endangered species
CSS - countryside stewardship scheme (UK)
CBD - rio convention on biological diversity
why should you randomly sample?
to avoid bias
phylogeny definition
the study of the evolutionary relationships between organisms
how are classification and phylogeny related?
phylogeny is the basis of classification
in what scenario do you measure frequency with a frame quadrat?
when the plants are too small to count, so you just count the number of squares in which they are present
community definition
all of the populations of living organisms in a particular habitat
niche definition
the role an organism plays in a community
how can you reduce the effect of chance?
by having a large sample size
what is gene flow?
the transfer of genetic material from one population to another (interbreeding)
classification definition
the process of placing living things into groups
what is taxonomy?
the study of classification
the binomial naming system
Genus + species
e.g. Homo sapiens
what is the 3 domain system?
archea, bacteria, eukarya
what is the 5 kingdom system?
protoctista, fungi, Animalia, plantae, prokaryotes
what replaced the 5 kingdom system? what changed?
the 3 domains system
the prokaryote kingdom was separated into 2 domains: archea and bacteria
intraspecific variation
variation within a species
interspecific variation
variation between different species
(inER = difERent)
continuous vs discontinuous variation
continuous variation is within a range with no distinct categories, discontinuous variation is when there are two or more distinct categories and no intermediates
what does standard deviation show?
the amount of variation from the mean
what does x̄ represent in the standard deviation formula?
the mean
why do adaptations in organisms develop?
because of evolution by natural selection
the 3 types of adaptations
behavioural
anatomical
physiological
example of convergent evolution
marsupial moles and placental moles
convergent evolution definition
when 2 species evolve similar characteristics independently of one another
what are selection pressures?
factors that create a struggle for survival e.g. predation, disease, competition
evidence that supports the theory of evolution (3)
molecular evidence (e.g. amino acid sequences)
fossil record evidence
DNA evidence
features of Animalia
eukaryotic, multicellular, heterotrophic
features of prokaryotae
prokaryotes (no nucleus), DNA is in loops or naked, no membrane-bound organelles
features of fungi
eukaryotic, single-celled or multicellular, chitin cell wall, feed by saprotrophic nutrition, multinucleate cytoplasm
features of protoctista
eukaryotic, mostly single-celled, autotrophic or heterotrophic nutrition
features of plantae
eukaryotic, multicellular, cellulose cell wall, photo autotrophic
what evidence led to the introduction of the 3 domain system?
molecular evidence
cell membrane evidence
the theory of natural selection
- individuals in a population show variation in their phenotypes
- some survive better in the face of selection pressures due to having advantageous characteristics
- these individuals reproduce and pass on the alleles for such characteristics
- over many generations the allele(s) increase in frequency in the population
what is student t-test used for?
to compare the means of data values of two populations
what are some implications of evolution on human populations?
pesticide resistance in plants
antibiotic resistance in bacteria
