Classification and biodiversity Flashcards
why is classification needed?
- before, organisms named bases of physical characteristics - not useful for international scientists as more than one name
- helps predict characteristics
- provides info about evolutionary links between organisms
taxonomic groups
domain
kingdom
phylum
class
order
family
genus
species
5 kingdoms
animal, plant, protist, fungi, prokaryote
3 domains
archaea, bacteria, eukarya
species
group of organisms able to reproduce to produce fertile offspring
characteristics of fungi
- unicellular or multicellular
- nucleus and other membrane bound organelles - cell wall made of chitin
- no chloroplasts - saprophytic feeders - absorb decaying matter
- store food as glycogen
- most have body of myecelium made of threads or hyphae
characteristics of plants
- store food as starch
- get nutrients by photosynthesis - autotrophic
- chloroplasts and chlorophyll
- nucleus and membrane bound ourganelles
- multicellular
characteristics of animals
- get nutrients by digestion - heterotrophic
- move with aid of cilia, flagella, contracting proteins
- multicellular
- nucleus and membrane bound organelles
- no chloroplasts
- food stored as glycogen
characteristics of protists
- mainly unicellular
- photosynthesis - autotrophic or ingestion of other organisms or parasitic
- some have chloroplasts
- nucleus and membrane bound organelles
prokaryotes
- nutrients absorbed by cell wall or photosynthesis
- no nucleus or membrane bound organelles
- unicellular
why is phylogeny helpful?
- shows us who has common ancestors
- shows how closely related organisms are
- classification can imply all organisms in same group are equivalent
how was theory of evolution developed?
- Lyell - suggested fossils evidence of animals millions of years ago
- Lyell and Hutton - uniformitarianism - idea that natural processes today were always present
- Darwin - Galapogus islands
- Wallace - worked on theory of eveolution
- Darwin and Wallace came to similar conclusions and published ‘The Origin of the Species’
natural selection
- Mutation - random - produces variation
- competition - eg. outruns predator - due to selelction pressure
- survival of the fittest - allele gives advantage for the selection pressure
- Live long enough to reproduce - allele passed onto offspring
- Larger proportion of population have advantageous allele over time
palaeontology - evidence for evolution
- fossil record - bones of dead organisms make imprints in rocks from millions of years ago
Comparative anatomy - evidence for evolution
- study of similarities and differences in anatomy of species
- homologous structure - appears different and may have different functions but has same underlying structure
- provides evidence for divergent evolution - species evolved from common ancestor
comparative biochemistry - evidence for evolution
- comparing proteins and DNA and biological molecules
- looking at order of DNA bases or amino acids
evolutionary embryology - evidence for evolution
- embryos of many different animals look similar - implies embryonic development has common origin
continuous variation
- characteristic that can take any value in a range
- gradual rather than distinct categories
- represented in frequency table then histogram
- controlled by genes and/or environment
discontinuous variation
- a characteristic that can only result in certain values
- variation determined purely by genetic factors
- eg. sex, blood groups
- represented in pie chart/ bar graph
when would you use a Spearman’s rank coefficient?
- when you want to know if there is an relationship between different measurements from the same sample
when would you use a T-test?
- to decide if there is a significant difference between 2 populations
- p=0.05—> then 95% not due to chance
when would you use standard deviation?
- to measure how spread data is from the mean
interspecific variation
varaition between different species
intraspecific variation
variation within a species
anatomical adaptations
- eg. teeth, bod covering, camouflage
- physical characteristics, visible
behavioural adaptation
- innate or learnt behaviours
- eg. playing dead, courtship, migration, hibernation
physiological adaptations
- eg. water holding, antibiotic production, poison
- non-visible processes in the body
analogous structures
- structures adapted to perform same function but have different genetic origin
- eg. tails of whales and fish
convergent evolution
- whe unrelated species develop similar traits
- happens when they live in same environment or have similar selection pressures
- eg. placental and marsupial mole - last common ancestor 100 million years ago - evolved separately in Americas and Australia
monoculture
growing just one species/variety of crop
eg. Irish potato famine - potatoes wiped out by a disease
species richness
no. of species living in an area
species evenness
a comparison of no. of individuals of each species in a community
endemism
group of organisms unique to particular habitat like an island or type of vegetation
eg. kiwi birds endemic to New Zealand
why is Simpson’s index used?
to measure level of biodiversity in an area
selective breeding
- choosing what to breed together o create desirable characteristics very similar to each other to give high yield and low wastage
- lack of genetic diversity - highly susceptible to pests and diseases
importance of genetic biodiversity
- larger gene pool - higher likelihood of advantageous allele for if environment changes
- all members of species have same genes but different alleles of that gene - more alleles then more genetically diverse
factors affecting genetic diversity
- mutations
- gene flow - interbreeding between population leading to alleles transferring
- selective breeding
- captive breeding programmes
- artificial cloning
genetic bottlenecks
- few individuals survive an event or change in environment reducing the gene pool
- eg. extinction event at end of last ice age wiped out lots of cheetahs - forced to inbreed reducing gene pool
genetic drift
- alleles lost due to chance in meiosis
- random nature of alleles passed on
founder effect
- small no. of individuals create new colony geographically isolated - reduces gene pool
how does climate change affect biodiversity?
- warming trend over last 50 years - more xerophytes
- at 3km sea temps rising - water expands - sea levels rise - floods low level land, extinction of plant and animals on ice caps
how does deforestation affect biodiversity?
- animals forced to migrate to other areas
- reduces species diversity
- reduces no. of trees
how does agriculture industry affect biodiversity?
- select few species grown eg. wheat with most grain
- deforestation to make room for crops
- removal of hedgerows
- monoculture - farms specialise in production of one crop that a limited no. of animals can eat
- pesticides and herbicides
in-situ conservation
- eg. marine conservation zones, wildlife reserves
- cheaper, organisms in natural habitat, maintains genetic biodiversity and evolutionary adaptations, preserves interdependent relationships
- require active management - restricting human access, feeding animals, controlled grazing, controlling poaching
ex-situ conservation
- seed banks - dried and stored at -20 degrees C to maintain viability, some die if frozen
- botanic gardens - plant provided with best resources to grow, wild relatives of selectively bred species underrepresented
- captive breeding programmes - zoos, aquatic centres, hard to maintain genetic diversity- artificial insemination to maximise diversity, aim to create stable population then release into natural environment - diseases, behaviour not learnt, different genetic makeup so may not breed
IUCN
- red list with conservation status of animals
- involved in CITES
CITES
- convention of international trade of endangered species
- international agreement limiting trade of endangered species
- may lead to increased price of species and lead to people breaking the law
Rio de Janeiro agreement
- signed by 150 countries to promote biodiversity
- in UK areas were chosen as Sites of special scientific interest - SSSIs
- when a new development is planned, an environmental impact assessment is submitted
