Section 7 Flashcards

(35 cards)

1
Q

SAMPLING METHODS

two types of Quadrat

what size

what number

A
  • point quadrat = use on grassland, doesnt squash species
  • frame quadrat
  • with largwr species = larger quadrats
  • uneven distribution = large number of smaller quadrats
  • the more quadrats = more reliable results
  • the greater number of species = greater number of quadrats
  • keep sampling till running mean is consistant
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2
Q

RANDOM SAMPLING

A
  • comparing two different areas
  • avoids bias, more reliable
  • tape measure at right angles 10mby10m
  • get random coordingates by using random number generators
  • placed quadrat in a standardised matter eg: left corner of the coordinate ( 0.25m^2) ( x5 to 1m then to area)
  • record abundance = frequency and % cover
  • repeat 20x till running mean is consistant
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3
Q

RANDOM SAMPLING

limitations

A
  • quadrats only covering a small part of the total area
  • unreprisentative
  • snapshot effect = only data one time
  • light and wind change throught the day
  • cannot be used to measure moving organisms
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4
Q

SYSTEMATIC SAMPLING

A
  • used when looking at the distribution and abundance
  • where there is a gradual change in communities
  • belt transet ( interuppted ( longer distances) or continuous )
  • frame quadrat layed alongside the line
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5
Q

RANDOM SAMPLING

limitations

A
  • only covers small total area
  • snapshot effect = one day
  • light and wind change throught the day
  • cant measure moving organisms
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6
Q

SAMPLING

abundance

A

frequency = quick idea of species, doesnt tell about distribution or density

% cover = data collected quickly , doesnt need to count individuals, not usedful when species overlap

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7
Q

COMMUNITY INERACTIONS
( 3 )

A
  • inter specific competition ( -/-)
  • predatation ( bad for prey )
  • herbivory ( not good for plants )
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8
Q

COMPETITION

inter and intra

what they compete for biotic/abiotic

A

inter = different species
intra = same species

biotic =
- food, mates, pollinators

abiotic =
- minerals, water, light, space

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9
Q

COMPETITION

competitive exclusion

A
  • 2 species competing for same resources cannot co exist due to occupying the same neiche
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10
Q

PREDATOR PREY RELATIONSHIPS

A

always more prey = more energy
- less passed to next level ( predator)
eg: used for respiration, not all eaten, excretion

  • predator number decrease due to low number of prey ( starve )
  • low number of predators increase number of prey ( less eaten )
  • higher number of prey = more food for predators decreasing prey
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11
Q

KEY WORDS

population

adaptation

ecology

carying capacity

A
  • all organisms of one species within an ecosystem
  • characteristics developed by different species, allowing them to better exploit their neiche
  • study of interactions between organisms and environment
  • maximum stable population size of a species that an environment can sustainibly support
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12
Q

KEY WORDS

community

ecosystem

neiche

habitat

A
  • all the popuations of all the differebt species in the same ecosystem of habitat
  • made up of a community and their interactions with the environment
  • the role organisms occupies within its environment
  • place which is the typical environment for an organism
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13
Q

POPULATION GRAPHS

three stages names

A
  • slow growth
  • rapid growth
  • stable state, no growth
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14
Q

POPULATION GRAPHS

slow growth
rapid growth
stable state

descriptions

A
  • small number of individuals reproduce slowly
  • rapid growth where the ever increasing number of individuals continue to reproduce
  • decline may be due to food supply or increased predation
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15
Q

POPULATION GRAPHS

why use log

A
  • have a wide range in the data
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16
Q

POPULATION GRAPHS

limiting factors

A

o2, food, disease, predators , space

17
Q

ECOLOGICAL SUCESSION

definiton

A
  • progressive chnage in the composition and diversity of the species in a community in one place over a period of time
18
Q

ECOLOGICAL SUCESSION

whats primary sucession

A

start in new habitat with no soil and no previous community

19
Q

ECOLOGICAL SUCESSION

whats a poineer species

A
  • can colonise a hostile env
  • overtime alter abiotic conditions
  • naking it less hostile to allow more species

eg: lichen

usedful features:

  • cope with hostile conditions
  • asexual reproduction
  • germinate quickly
20
Q

ECOLOGICAL SUCESSION

secondary sucession

A
  • starts from bare soil with a previous community
  • process will be quicker due to having soil
21
Q

ECOLOGICAL SUCESSION

whats a climax community

whats a plaigoclimax community

A
  • stable community at the end of ecological sucession
  • area where the influneces of humans have prevented ecosystems from developing further eg: by mowing, grazing and burning. stopped reaching climax community
22
Q

ECOLOGICAL SUCESSION

overall discribing sucession

A
  • pioneer species such a s lichens are able to colonise in hostile environments
  • they chnage the abiotic conditions = less hostile, more stable
  • this allows more species to grow, and it is now less suitable for pioneer species
  • new species can outcompete pioneer species
  • overtime many species flourish = climax community
23
Q

MARK - RELEASE - RECAPTURE

equation

A

first marked / total = caught marked / 2nd pop

24
Q

MARK - RELEASE - RECAPTURE

assumptions

A
  • the roportion of marked to unmarked in 2nd sample = marked to unmarked as a whole
  • makes individuals when releaced distribute themselves evenly amoungst the remainder of the population
  • no immigration or emmigration
  • no birth or death occours
  • method of marking isnt harmful and doesnt affect predation
  • mark isnt lost or rubbed off
25
SPECIATION variation in phenoytpe genetic factors
mutations = main source of variation - sudden changes to genes and chromasomes = new alleles, which may or may not pass on meiosis = new combinations of alleles = crossing over and independent assornment random fertalisation of gametes = in sexual reproduction new combinations of alleles = offspring from different parents
26
SPECIATION variation in phenoytpe environmental influences
- environment excerts infulence on all organisms - influences ways genes are expressed - genes set limits but environment determine where within the limits organisms lie environment = abiotic
27
SPECIATION variation in phenoytpe what mostly causes variation
- conbined affects of genetic and environment = hard to destingusish
28
SPECIATION Hardy weingburg
- allele frequencies in a large pop should remain stable from one generation to the next - depends on all genotypes having the same reproductive success, selection pressures: predation, disease and compatition - they determine the frequency of alleles within a gene pool
29
SPECIATION over production
all species have potential for exponential growth - in nature populations rarely grow at this rate - death rate = extremely high - predation - competition - food - water natural disasters eg fire or disease - evolved high reproductive rate - little parental imput and high death rate = senures a large pop survives - lower reproductive rate = high parental imput, low death rate = mainatain population size
30
Over production and natural selection
large pop = genetic variation = intraspecific comp = better adapted to survive = reproduce = pass on favoured allele combination = increase allele frequecy
31
SPECIATION allopatric
- geographical barrier - reproductive isolation - seperate gene pools - variation due to mutation - diff selection pressures - differental reproductive sucess - change in allele frequency - formation of diff species
32
SPECIATION sympatric
- mutation reproductive isolation - seperate gene pools - variation due to mutation - diff selection pressures - differental reproductive sucess - change in allele frequency - formation of diff species
33
SPECIATION genetic drift
can take place in populations due to chance = changes in allele frequency small = due to chance events
34
SPECIATION types of variation for sympactic
ecological = populations inhabit different habitats temporal = the breeding seasons behavoiural = mating is often preceded by courtship which is stimulated by the colour or markings of the opposite sex mechanical = no penis in vagina gamaetic = sperm destroyed by chemicals in vagina / pollen failing to germinate hybrid sterility = cannot produce viable gametes
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