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human impact Flashcards

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1
Q

definition for biodiversity

A

number of species and individuals of each species in a given place at any time

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2
Q

definition for endangered

A

a species that is at risk of extinction

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3
Q

definition for extinct

A

a species that has no living members

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4
Q

definition for planetary boundaries

A

a threshold value for a global process that is affected by human activity. crossing these boundaries could generate abrupt/irreversible environmental changes

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5
Q

definition for alien species

A

a species introduced to a habitat by man, will compete with the native species and generally upset the balance of the ecosystem

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6
Q

definition for gene pool

A

all of the alleles of all the genes in a population

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7
Q

definition for SSSI

A

site of specific scientific interest

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8
Q

definition for CITES

A

convention on international trade in endangered species (reducing if people can buy certain things, therefore allowing declining numbers to increase)

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9
Q

definition for conservation

A

protection, preservation, management and restoration of natural habitats and their ecological communities - to enhance biodiversity while allowing for suitable human activity

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10
Q

definition for monocultures

A

growth of large numbers of genetically identical crop plants in a defined area

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11
Q

definition for deforestation

A

removal of trees at faster rate than they are being replanted regenerated

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12
Q

definition for sustainable forestry

A

where trees are replaced / replanted / sufficient regeneration time is allowed so trees can be harvested indefinitely

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13
Q

definition for selective cutting

A

felling only some trees, leaving others in place

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14
Q

definition for coppicing

A

cutting down trees close to the ground and leaving them to re-grow for 5-7 years

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15
Q

definition for overfishing

A

rate at which fish are harvested exceeds the rate at which they reproduce

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16
Q

definition for environmental impact assessment

A

predicted environmental impact of any proposed development - use data collected by uninterested 3rd party

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17
Q

definition for ecotourism

A

responsible travel to natural areas that conserves the environment and improves the wellbeing of local people

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18
Q

definition for ecosystem

A

balanced biological system where all components (living and non-living) interact in a particular location, there is energy flow and nutrient cycling within the ecosystem

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19
Q

definition for habitat

A

place where an organism lives

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20
Q

definition for niche

A

role and position of an organism within its environment, including all interaction with the biotic and abiotic factors of its environment

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21
Q

definition for ecology

A

study of relationships between living organisms, including humans, and their physical environment

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22
Q

definition for environment

A

factors in a habitat which affect an organism - both living and non-living

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23
Q

definition for biotic

A

part of the environment that is living (e.g. disease, predation)

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24
Q

definition for abiotic

A

part of the environment of an organism that is non-living (e.g. temperature, pH, light, oxygen availability)

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25
definition for limiting factors
aspects of the environment (either physical or biotic) which restricts population size - causes environmental resistance to population growth
26
definition for species
a group of organisms which share a large number of characteristics and which can interbreed to produce fertile offspring
27
definition for carrying capacity
maximum number of individuals that can be sustained by a habitat
28
definition for density dependent factor
factors that affects population size and is affected by population size
29
what is the impact of niche overlap avoidance?
reduces competition (niches overlap less)
30
what does the lag phase represent (in animal populations)?
adjustment to the environment and few reproducing individuals
31
what does the log phase represent (in animal populations)?
rapid population growth, birth rate>death rate, no limiting factors, population doubles per unit time
32
what does the stationary phase represent (in animal populations)?
limiting factors, birth rate = death rate, has reached carrying capacity
33
what's the difference between stationary phase in animals and bacteria?
animals has carrying capacity
34
what does the death phase represent (in animal populations)?
*new* : disease, predator meteorite, natural disaster, introduced competition
35
what does the lag phase represent (in bacterial/yeast populations)?
switching on genes and synthesising enzymes, replicating DNA
36
what does the log phase represent (in bacterial/yeast populations)?
reproductive rates > death rate no limiting factors, rapid population growth
37
what does the stationary phase represent (in bacterial/yeast populations)?
reproductive rates = death rate, no carrying capacity
38
what does the death phase represent (in bacterial/yeast populations)?
food/nutrients run out, (for aerobic bacteria) - oxygen can run out (not for anaerobic bacteria), toxic products build up - e.g. ethanol from yeast
39
(general pattern for predator-prey cycle) number of predators increases as there is more/less prey available
more
40
(general pattern for predator-prey cycle) number of prey decreases/increases as more predators
decreases
41
(general pattern for predator-prey cycle) number of predators increases/decreases as there are now less prey available
decreases
42
(general pattern for predator-prey cycle) number of prey increases/decreases as there are now fewer predators
increases
43
give the equation that shows a population size remains constant
birth rate and immigration = death rate and emigration
44
what steps would you take to sample plants on a field? (4 points)
- divide the area into a grid - use a random number generator to get coordinates - count the number of plants in the quadrat - repeat 10 times and calculate a mean (or repeat at different time of day / season / area)
45
why is energy lost between trophic levels?
- not everything is eaten (e.g. fur, bones) - egestion (faeces - egestion of indigestible parts, e.g. cellulose) - respiration to provide energy for movement, active transport, energy is released as heat - excretion of energy in urea (humans) / uric acid (birds) / ammonia (fish
46
why does a food chain not go beyond quaternary consumer?
there is not enough energy to sustain another trophic level (as energy is lost at each level)
47
positive and negative of pyramid of numbers
positive: easy to construct negative: can be inverted a it doesn't take into account biomass
48
positive and negative of pyramid of biomass
positive: more accurate ( can be inverted if short lifespan, less likely to be inverted negative: less easy to calculate
49
positive and negative of pyramid of energy
positive: most accurate ( represents energy transferred in each trophic level) negative: most difficult to calculate
50
define species evenness
the number of individuals of each species
51
define species richness
number of different species
52
define simpsons diversity index
measure of number of species, but also considers how those species are distributed (measure of biodiversity)
53
what should the value for simpsons diversity index be between?
0 and 1
54
define intraspecific competition
competition between individuals of one species
55
define interspecific competition
competition between individuals of different species
56
what are the assumptions for capture-mark-recapture?
- no net change in population - no emigration/immigration - the mark is not toxic and doesn't attract predators (doesn't impact survival) - there is time for the animals to disperse evenly (randomly distribute)
57
what is primary succession?
succession in an area where no ecosystem previously existed (bare rock) - e.g. volcanic eruption or glacier
58
how do living organisms get to the new island?
- ocean and wind currents carry spores/seeds/small plants and animals - birds flying over island carry spores etc
59
what is a first producer?
pioneer species (first species to colonise an area in succession)
60
give 2 examples of producers
lichen, moss
61
what is produced after lichen and moss?
grass, then ferns and eventually flowering plants, then insects etc
62
define climax community
equilibrium has been reached, no further succession
63
what is secondary succession?
(primary succession) occurring in an area where an ecosystem has previously existed
64
whats the first species to colonise an area in succession?
pioneer species
65
what factors affect succession?
- migration - level of interspecific competition - facilitation
66
why does migration affect succession?
varies depending on how easy it is for a new species to colonise the area
67
why does the level of interspecific competition affect succession?
if competition is stronger, succession will be faster
68
why does facilitation affect succession?
each species alters the surrounding environment, allowing new species to grow
69
what does facilitation mean?
when one species positively impacts another species
70
what is nitrogen used for?
proteins, ATP, nucleic acids, amino acids and chlorophyll
71
what is the bond between nitrogen atoms?
triple (covalent) bond
72
what are the 2 products nitrogen can be made into (using haber process and lightning) ?
ammonium (NH4+) and nitrate (NO3-)
73
what is it called when nitrogen is converted into either nitrate or ammonium?
nitrogen fixation
74
what do animals and plants receive from the nitrogen fixation?
nitrate ions
75
what is it called when plants and animals turn into ammonium?
ammonification (decomposition, putrefaction)
76
what is the effect of lightning in nitrogen fixation?
breaks nitrogen molecules apart
77
what is it called when nitrate ions turn back into atmospheric nitrogen?
denitrification
78
what is denitrification done by?
pseudomonas
79
when do pseudomonas do denitrification?
in waterlogged conditions
80
what is pseudomonas?
type of bacteria
81
name the 5 bacteria in the nitrogen cycle
Pseudomonas, Azotobacter, Rhizobium, Nitrobacter, Nitrosomonas
82
what do Nitrobacter and Nitrosomonas do?
nitrification (turn NH4+ to NO2- to NO3 -)
83
what is the haber process used for?
making fertiliser
84
what are the 2 types of bacteria used for nitrogen fixation to ammonium?
azotobacter and rhizobium
85
what does azotobacter do?
it is free living in soils, assists with nitrogen fixation to ammonium
86
what does rhizobium do?
has symbiotic and mutualistic relationship, lives in root nodules of legumes
87
why is rhizobium pink in colour?
due to the presence of leghaemoglobin (like haemoglobin and binds to oxygen)
88
what is the function of leghaemoglobin?
creates an oxygen-free environment
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