Classification and biodiversity Flashcards
1
Q
why is classification needed?
A
- identifying species - all scientists use the same name for an organism, can easily see which species an organism belongs to
- helps predict characteristics - members of same groups share characteristics
- provides info about evolutionary links between organisms - same group probably share characteristics bc evolved from common ancestor
2
Q
binomial nomenclature
A
- all species given a name consisting of genus and species
- no 2 species have the same generic and specific name
3
Q
8 taxonomic groups
A
domain
kingdom
phylum
class
order
family
genus
species
4
Q
5 kingdoms
A
animal, plant, protist, fungi, prokaryote
5
Q
why is there now 6 kingdoms?
A
- prokaryote kingdom split into archaebacteria and eubacteria
archaebacteria: - can live in extreme environments
eubacteria: - found in all environments
- contain peptidoglycan in cell wall
6
Q
3 domains and their characteristics
A
archaea
- 70s ribosomes
- RNA polymerase contains 8-10 proteins
bacteria
- 70s ribosomes
- RNA polymerase contains 5 proteins
eukarya
- have 80s ribosomes
- RNA polymerae contains 12 proteins
7
Q
species
A
group of organisms able to reproduce to produce fertile offspring
8
Q
characteristics of fungi
A
- 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
9
Q
characteristics of plants
A
- store food as starch
- get nutrients by photosynthesis - autotrophic
- chloroplasts and chlorophyll
- nucleus and membrane bound ourganelles
- multicellular
10
Q
characteristics of animals
A
- 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
11
Q
characteristics of protists
A
- mainly unicellular
- photosynthesis - autotrophic or ingestion of other organisms or parasitic
- some have chloroplasts
- nucleus and membrane bound organelles
12
Q
characteristics of prokaryotes
A
- nutrients absorbed by cell wall or photosynthesis
- no nucleus or membrane bound organelles
- unicellular
13
Q
how was the 3 domain system created?
A
- observing differences in sequences of nucleotides in ribosomal RNA and cells’ membrane lipid structure and sensitivity to antibiotics
14
Q
why is phylogeny helpful?
A
- shows us who has common ancestors
- shows how closely related organisms are
- classification can imply all organisms in same group are equivalent
15
Q
how does phylogenetic tree work?
A
- earliest species at base of tree, most recent at the tips of branches
- the closer the branches, the closer the evolutionary relationship
- 2 descendants that split from same node are sister groups
16
Q
advantages of phylogeny
A
- produces continuous tree, classification requires discrete groups - not forced to put organisms in a group they may not fit
- doesn’t have the hierarchal nature of classification which implies diff group sin the same rank are equivalent eg. cats and orchids - existed for v diff time periods, 35 cat species and 20,000 orchid species
17
Q
how was theory of evolution developed?
A
- Darwin - Galapogus islands - diff islands had diff finches, beaks and claws diff shapes and sizes. Bird with beaks more suited to food availability more likely to survive and pass on characteristic to offspring
- Wallace - worked on theory of evolution
- Darwin and Wallace came to similar conclusions and published ‘The Origin of the Species’
18
Q
natural selection
A
- 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
19
Q
palaeontology - evidence for evolution
A
- fossil record - bones of dead organisms make imprints in rocks from millions of years ago
- fossils or bacteria and algae found in oldest rocks, fossils of more complex vertebrates found in more recent rocks - simple life evolves gradually into more complex
- plant fossils appear before animal fossils - consistent with fact that animals require plants to survive
- similarities in anatomy of fossils shows how closely related they are
20
Q
limitations of palaeontology
A
- many organisms are soft-bodied and decompose before having a chance to fossilise
- conditions required for fossils to form often aren’t present
- fossils could be destroyed by Earth’s movements - volcanoes
- many could still be undiscovered
21
Q
Comparative anatomy - evidence for evolution
A
- study of similarities and differences in anatomy of living species
- homologous structure - appears different and may have different functions but has same underlying structure
- provides evidence for divergent evolution
22
Q
divergent evolution
A
- diff species with diff set of adaptive features have evolved from a common ancestor
- occurs when closely related species diversify to adapt to new habitats as a result of migration or loss of habitat
23
Q
comparative biochemistry - evidence for evolution
A
- comparing proteins, DNA and biological molecules
- most variability in the structure of a molecules doesn’t change its function bc most variability occurs outside its functional regions - the changes are ‘neutral’ and happen at a regular rate
- look at order of DNA bases, no. of differences plotted against rate of neutral base pair substitutions
- from this scientists can estimate the point the species shared a common ancestor
24
Q
evolutionary embryology - evidence for evolution
A
- embryos of many different animals look similar - implies embryonic development has common origin
25
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
26
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
27
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
28
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
29
when would you use standard deviation?
- to measure how spread data is from the mean
30
interspecific variation
varaition between different species
31
intraspecific variation
variation within a species
32
genetic causes of variation
- individuals in a species inherit different alleles of a gene
- mutations - cause changes to proteins and therefore physical and metabolic characteristics
- meiosis - independent assortment, crossing over
- sexual reproduction - down to chance which sperm fertilises the egg
33
environmental causes of variation
environment has a greater impact on plants than animals due to their lack of mobility
- eg. scars
- diet - if it is poor, you may only grow to a certain height
- sun - skin produces more melanin in sunlight, more light for plants causes them to grow larger
34
anatomical adaptations
- physical characteristics, visible
- eg. teeth, body covering, camouflage, mimicry (eg. hoverfly)
35
behavioural adaptation
- innate or learnt ways an organism acts
- eg. playing dead, courtship, migration, hibernation
36
physiological adaptations
- eg. water holding, antibiotic production, poison
- processes inside the body
37
analogous structures
- structures adapted to perform same function but have different genetic origin
- structures are different
- eg. tails of whales and fish
38
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 but have similar shape, feeding techniques and locomotion
39
antibiotic-resistant bacteria as example of evolution
- bacteria reproduce rapidly so evolve in a short time
- a mutation in a type of bacteria provided resistance to a type of antibiotic
- when bacteria exposed to the antibiotic, resistant ones survived and reproduced, passing on the allele for resistance onto their offspring
- over time, the no. of resistant individuals increased
40
peppered moths as example of evolution
- before industrial revolution, most peppered moths were pale coloured - camouflage against light tree bark, increasing chance of survival
- during industrial revolution many trees became darker (covered in soot or lost lichen due to air pollution) - dark moths better adapted and more survived and reproduced, increasing frequency of dark allele in population
41
sheep blowflies as example of evolution
- lay eggs on faecal matter around sheep's tail - larvae hatch and cause sores
- pesticide introduced to kill blow flies
- blowflies developed high level of resistance to pesticide and survived exposure to it, passing on allele, resistant population evolves
42
monoculture
growing just one species/variety of crop
eg. Irish potato famine - potatoes wiped out by a disease
43
species richness
no. of species living in an area
44
species evenness
a comparison of no. of individuals of each species in a community
45
endemism
group of organisms unique to particular habitat like an island or type of vegetation
eg. kiwi birds endemic to New Zealand
46
why is Simpson's index used?
to measure level of biodiversity in an area
47
reasons a sample is never entirely representative of a habitat
- sampling bias - eg. sampling an area that looks interesting, can be reduced by random sampling
- chance - eg. sample of 5 worms may be the longest 5 in the habitat, reduced by using large sample size
48
methods of sampling animals
- pooter
- sweep nets - insects in long grass
- pitfall traps - hole dug, insects fall in
- tree beating - white cloth layed under tree, tree shaken to dislodge invertebrates
- kick sampling - kick river bank or bed to disturb it, hold net downstream to catch organisms
49
methods of sampling plants
- point quadrat - a frame with a horizontal bar, pins pushed through bar to reach ground at set intervals, species where pin touches is recorded
- frame quadrat - square frame in grid of equal sections, types and no. of species in each section of quadrat recorded
50
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
51
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
52
factors affecting genetic diversity
- mutations
- gene flow - interbreeding between population leading to alleles transferring
- selective breeding
- captive breeding programmes
- artificial cloning
- natural selection
- genetic bottlenecks
- the founder effect
- genetic drift
53
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
54
genetic drift
- alleles lost due to chance in meiosis
- random nature of alleles passed on
55
founder effect
- small no. of individuals create new colony geographically isolated - reduces gene pool
56
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
57
how does deforestation affect biodiversity?
- animals forced to migrate to other areas
- reduces species diversity as it destroys their habitat and food source
- reduces no. of trees
58
how does agriculture industry affect biodiversity?
- select few species grown eg. wheat with most grain
- deforestation to make room for crops
- removal of hedgerows - enables them to use large machinery to help plant, fertilise and harvest crops - destroys habitat of birds, hedgehogs, mice
- monoculture - farms specialise in production of one crop that a limited no. of animals can eat
- pesticides and herbicides
59
reasons for maintaining biodiversity
aesthetic
- presence of plants and animals enriches our lives
- provides inspiration for musicians and writers
- reduces stress
economic
- soil erosion and desertification as result of deforestation - can't grow crops
- non-sustainable removal of resources leads to collapse of industry in an area
- medicine
- tourism
ecological
- all organisms are interdependent on each other for survival
- keystone species - disproportionately large effect on environment
60
in-situ conservation pros and cons
- 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
61
in situ conservation techniques
- controlled grazing - only allowed in particular areas to allow species time to recover
- restricting human access
- controlling poaching - defences, fines
- feeding animals - ensures more organisms survive
- reintroduction of species
- removal of invasive species
- halting succession
62
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
63
IUCN
- red list with conservation status of animals
- involved in CITES
64
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
65
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
