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Biology IB YR12-13 > C4.1 Populations and Communities > Flashcards

C4.1 Populations and Communities Flashcards

1
Q

population

A

interacting groups of organisms of the same species living in an area

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2
Q

sample

A

A subset of a whole population of habitat used to estimate the values that might have been obtained if every individual or response was measured

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3
Q

random sampling

A

A method of choosing a sample from a population without bias

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4
Q

sampling error

A

Statistical errors when a sample doesn’t represent the whole population

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5
Q

random errors

A

Unknown unpredictable differences
imprecision and uncertainty

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6
Q

systematic errors

A

Inaccuracy
- due to faults in experiment design

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7
Q

how are random errors eliminated

A

by taking average

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8
Q

how are systematic errors eliminated

A

with better designs

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9
Q

stratified sampling

A

two or more different habitat types

proportional area of different habitat types and samples each one accordingly

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10
Q

systematic sampling

A

when area includes an environment gradient

transect used to sample systematically along the environmental gradient

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11
Q

random quadrat sampling

A

used to study populations and communities

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12
Q

population size formula

A

(mean density per quadrat x total area)/ area of each quadrat

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13
Q

standard deviation variation

A

quantitative measure of the distribution of the values in a data set

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14
Q

standard deviation range

A

difference between largest and smallest data values

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15
Q

standard deviation

A

spread of a set of normally distributed data from the mean of sample

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16
Q

small standard deviation

A

data more reliable

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17
Q

normal distribution

A

data set distribution that is symmetrical about the mean

bell shaped curve

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18
Q

large standard deviation

A

unlikely to be significant too small - certainly significant

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19
Q

df

A

n - 1

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20
Q

one method to estimate population size for motile organisms

A

capture - mark - release - recapture - method

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21
Q

capture - mark - release - recapture - method

A

sample taken
animals taken, marked, recaptured, resampled
calculation made - number marked animals compared to size of resampled population compared to total population

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21
Q
A
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22
Q

Lincoln Index

A

population size = (M x N / R)

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23
Q

M Lincoln Index

A

number of animals captured

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24
N Lincoln Index
number of animals recaptured
25
R Lincoln Index
number of marked animals recaptured
26
what assumptions have to be made for a Lincoln Index
- mixing is complete - marked individuals have spread out - marks are not removed - marks are not harmful - equally easy to catch each individual - no immigration/emigration/deaths/births
27
carrying capacity
maximum number of individuals of a species that can be supported by a given environment resources can run low, competition, limiting factors prevent population from increasing further
28
negative feedback
feedback that tends to counteract any deviation from equilibrium and promotes stability
29
density dependant factors
factors that lower the birth rate or raise death rate as a population grows
30
biotic factors that limit population growth
internal density dependant factors external density dependant factors
31
internal density dependant factors
fertility/size of breeding territory
32
external density dependant factors
increased predation and pathogen or pests in dense populations
33
Density independant
will affect the populations of all species in an ecosystem weather, climate, natural disasters
34
Density dependant
varying effects on the population of different species - define carrying capacity - tends to push population back towards carrying capacity
35
exponential growth
increasing rate of growth occurs in air ideal and unlimited environment limiting factors dont restrict plentiful resources favourable abiotic components
36
sigmoid growth curve
s shape population curve shows an initial rapid growth and then slows down as carrying capacity is reached
37
exponential growth
limiting factors dont restrict growth of a population
38
transition phase
increase in number is slow limiting factors begin to affect the population
39
plateau phase
limiting factors restrict population to carrying capacity
40
NIEM phases
natality mortality immigration emigration
41
natality
birth rate
42
mortality
death rate
43
immigration
movement into population
44
emigration
departure from population
45
duckweed features
aquatic plants staple diet for ducks and other aquatic birds rapidly growing used as a model system for studies in population ecology
46
communities in ecosystems
a group of different species living in an area biotic parts of the ecosystem
47
intraspecific competition
competition between individuals of the same species
48
interspecific competition
competition between individuals of different species
49
cooperation
action or process of working together to minimise direct competition
50
wildebeast in competition
territory fight - intraspecific
51
hyenas in terms of cooperation
hunt together - clans cooperation
52
insects in terms of group work
group work (social insect) bees, wasp, ants super organism - all are genetically identical altruistic behavior leaf cutter ants
53
mutualism
symbiosis interaction in which both species derive benefit can increase carrying capacity
54
parasitism
parasite organisms benefits at expense of host lower carrying capacity of host
55
pathogenicity
capacity of a microbe to cause damage to a host resulting in disease can reduce carrying capacity of infected population
56
alturism
behaviour of an animal that benefits another at its own expense increases the number of offspring produced by recipient and decreases that of the alturist
57
root nodules in fabaceae legume
small swelling on the root of plants that contain symbiotic nitrogen fixing bacteria
58
rhizobium
bacterium living in root nodules fixes nitrogen gas to form ammonium ions enables them to live in nitrate deficiet areas need glucose for respiration aerobic needs lots of energy large amounts of ATP
59
what does rhizobium contain
nitrogenase (enzyme) which catalyses nitrogen fixation oxygen exclusion necessary - same size and shape so causes blockage)
60
mycorrhizae in orchidaceae
fungus that grows in association with roots of a plant in a symbiotic relationship key role in orchid germination seed is small so it gets nutrients from fungi in turn fungi gets glucose
61
corals and zooxanthellae
mutually beneficial polyps connect - sharing of nutrients algae live in endodermis coral provides algae with protected environment and Co2 for photosynthesis
62
grey squirell and red squirell
alien invasive species where the grey squirell removed the red completely
63
who investigated competitve exclusion
joseph connell
64
what did joseph connell investigat
2 species of banacle 2 species couldnt grow in the same area because of difference in niches led to competitive exclusion
65
hypothesis
states that there is a statistially significant difference between 2 variables
66
null hypothesis
no statistically significant difference between 2 variables
67
independant variable
experiment changes one variable measures effect on dependant
68
control variable
variables kept constant
69
chi squared test
tests significance of deviations between numbers observed (O) and numbers expected (E)
70
predator-prey relationships
interrelationships of population size due to predation of one species on another controlled by negative feedback mechanisms that control population densities
71
top down control
changes to the food chain occur at the top trophic level and then impact on the trophic levels lower in the food chain predator controlled food web
72
bottom up control
changes to food chain occur at the lowest trophic level and then impact on the trophic levels higher in the food chain imitation due to resources that allow growth etc
73
allelopathy
chemical inhibition of one plant by another, due to the release of chemicals that act as germination or growth inhibitors
74
how can allelopathy be carried out in plants
- releasing chemical compounds from roots to soil - gas from stomata in leaves - leaves dropping with toxic chemicals
75
examples of allopathic plants
cabbage mustard kale radish
76
secretion of antibiotics
penicilin by alexander flemming in 1929 fungi naturally produces antibiotics to kill or stop bacteria growth
77
how is penicillin allopathic
kill and inhibit bacteria medicine and antibiotics

Biology IB YR12-13 (33 decks)

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