20. Human Influences on Ecosystems + 21. Biotechnology and genetic modification Flashcards
1
Q
What has increased food supply?
A
Modern technology
2
Q
In what 4 ways has modern technology helped increase food supply?
A
agricultural machinery
chemical fertilisers
insecticides and herbicides
selective breeding
3
Q
How has agricultural machinery helped increase food supply?
A
Agricultural machinery has replaced humans and improved efficiency due to the ability to farm much larger areas of land
4
Q
How have chemical fertilisers helped increase food supply?
A
Chemical fertilisers improve yields – fertilisers increase the amount of nutrients in the soil for plants, meaning that they can grow larger and produce more fruit
5
Q
How have insecticides and herbicides helped increase food supply?
A
Insecticides and herbicides – these chemicals kill off unwanted insects and weed species, meaning that there is less damage done to plants and fruit lost to insects (insecticides), as well as reducing competition from other plant species (herbicides)
6
Q
How has selective breeding helped increase food supply?
A
Selective breeding – animals and crop plants which produce a large yield are selectively bred to produce breeds that reliably produce high yields
7
Q
What is monoculture?
A
Monoculture farming means that on a given area of agricultural land only one type of crop is grown (eg trees for palm oil grown in Indonesian rainforest)
8
Q
What is a problem with monoculture relating to biodiversity?
A
This large scale growth of a single variety of plant does not happen naturally in ecosystems, where there are usually many different species of plants growing which, in turn, support many species of animals (high biodiversity)
In monocultures, biodiversity is much lower
9
Q
What is a problem with monoculture relating to pests?
A
Another issue with monocultures is the increase in pest populations – if a particular pest feeds on a crop, farming it in large areas repeatedly means there is an ample supply of food for the pest, causing the population to increase
10
Q
What is a problem with monoculture relating to insecticides?
A
Often farmers will spray insecticides onto crops in order to control the pests. This leads to:
harmless insects being killed as well
pollution by pesticides (which are often persistent chemicals which accumulate in food chains)
in many instances where they are used repeatedly for specific pests, the pests may eventually become resistant to them, reducing their effectiveness
11
Q
What is a problem with farming livestock In developed countries?
A
In developed countries, large numbers of livestock are often kept in an area that would not normally be able to support more than a very small number
12
Q
What are these livestock given which is harmful?
A
They are often
fed high energy foods,
regularly given medication such as antibiotics as a preventative measure against disease and
kept in artificially warm temperatures and small spaces that do not allow for much movement
13
Q
What are 3 ecological issues involved with intensive farming?
A
reduction in biodiversity in areas where large amounts of land are used to graze cattle (as only grass is grown so in effect it becomes a monoculture)
overgrazing can lead to soil erosion
large numbers of cattle produce large amounts of methane, a greenhouse gas
14
Q
When does a famine occur?
A
When people do not receive enough food, famine occurs
15
Q
What can cause a famine? (4)
A
natural disasters, such as drought and flooding,
increasing population,
poverty, and
unequal food distribution
16
Q
What has to happen to food production as population increases?
A
As the global human population increases, food production must also be increased to support the increasing population
17
Q
Why is it bad that the food production industry has to keep increasing?
A
This is a problem as more land is required to grow crops and animals, meaning that deforestation is happening at an increasing rate, and there is also an increasing amount of greenhouse gases emitted from animal production
18
Q
Why is an accumulation of greenhouse gases a problem?
A
Greenhouse gases cause global warming, which is a worldwide issue that leads to increased natural disasters, such as tropical storms and drought, as well as rising sea levels, which floods homes and decreases the amount of habitable land
19
Q
What is the increasing human population doing in relation to habitats?
A
The increasing human population of the planet is causing destruction of many habitats from rainforest to woodland to marine
20
Q
How can habitats be destroyed?
A
Many habitats are destroyed by humans to make space for other economic activities, or by pollution from these activities, and this reduces the biodiversity of these areas
21
Q
Why is it harmful when habitats are destroyed?
A
This interrupts food chains and webs, meaning that more species may die because their prey is gone
22
Q
What are the 3 main reasons for habitat destruction?
A
clearing land for farming and housing
extraction of natural resources
marine pollution
23
Q
How does clearing land for farming and housing contribute to habitat destruction?
A
crops, livestock and homes all take up a large amount of space
as there is an increasing population and demand for food, the amount of land available for these things must be increased by clearing habitats such as forests (deforestation)
24
Q
How does extraction of natural resources contribute to habitat destruction?
A
natural resources such as wood, stone and metals must be gathered to make different products.
therefore many trees are cut down, destroying forest habitats. in addition, some resource extraction takes up a large amount of space
for example: mining, which means that the land must be cleared first
25
How does marine pollution contribute to habitat destruction?
human activities lead to the pollution of marine habitats
in many places, oil spills and other waste pollutes the oceans, killing sea life
in addition, eutrophication can occur when fertilisers from intensively farmed fields enters waterways
this causes a huge decrease in biodiversity in these areas as most aquatic species living in these waterways die from lack of oxygen
26
What is deforestation?
Deforestation is the clearing of trees (usually on a large scale)
27
How can deforestation be a sustainable practice?
If trees are replaced by replanting it can be a sustainable practise
28
Why does deforestation usually occur?
Generally the trees are being cleared for the land to be used in a different way (for building, grazing for cattle, planting of monocultures such as palm oil plantations etc) and therefore it is not sustainable
29
What is a particularly severe example of habitat destruction?
As the amount of the Earth’s surface covered by trees decreases, it causes increasingly negative effects on the environment and is a particularly severe example of habitat destruction
30
What are 4 undesirable effects of deforestation?
Undesirable effects of deforestation include:
Extinction of species
Loss of soil
Flooding
Increase of carbon dioxide in the atmosphere
31
How is extinction of species an undesirable effect of deforestation?
forest habitats, especially tropical rainforest s, have a huge range of biodiversity and as habitat is destroyed it causes the loss of large numbers of plant and animal species
many of these species are only found in these areas therefore will become extinct
32
How is loss of soil an undesirable effect of deforestation?
tree roots help to stabilise the soil, preventing it from being eroded by rain
trees will usually take up nutrients and minerals from the soil through their roots
without trees, nutrients and minerals will remain unused in the soil so will be washed away into rivers and lakes by rain (leaching)
this loss of soil nutrients is permanent and makes it very difficult for forest trees to regrow, even if the land is not cultivated with crop plants or grass for cattle
33
How is flooding an undesirable effect of deforestation?
without trees the topsoil will be loose and unstable so will be easily washed away by rain, increasing the risk of flash flooding and landslides
34
How is increase of carbon dioxide in the atmosphere an undesirable effect of deforestation?
trees carry out photosynthesis during which they take in carbon dioxide and release oxygen
the removal of significant numbers of trees means less carbon dioxide is being removed from the atmosphere (and less oxygen released)
when areas of land in forests are cleared for land use, the trees are of ten burned as opposed to being cut down. this releases carbon dioxide (it is an example of combustion), further increasing carbon dioxide levels in the atmosphere and contributing to global warming
35
What types of pollution have human activities caused?
Human activities have led to the pollution of land, water and air
36
What sources can pollution come from?
industry and manufacturing processes,
waste and discarded rubbish, - chemicals from farming practices,
nuclear fall-out,
untreated sewage
37
What is the source/cause for untreated sewage?
lack of sewage treatment plants in inhabited areas due to poor infrastructure lack of money meaning sewage runs / is pumped into streams or rivers
38
What is the source/cause for chemical waste?
chemicals such as heavy metals ike mercury can be released from factories into rivers and oceans or leach into land surrounding the factories
39
What is the source/cause for discarded rubbish?
much rubbish consists of plastic that is either discarded or buried in landfills
40
What is the source/cause for fertilisers?
runoff from agricultural land applied in too high concentration
41
What is the source/cause for insecticides and herbicides?
sprayed on crops to prevent damage by insects and growth of weeds
42
What is the source/cause for nuclear fallout?
radioactive particles that get into the environment from accidental leakage from nuclear power plants or explosion of a nuclear bomb
43
What is the source/cause for methane?
cattle farming, rice fields, landfills
44
What is the source/cause for carbon dioxide?
produced when fossil fuels are burnt, also released when trees are burnt to clear land for human use
45
What is the effect of untreated sewage on the environment?
provides a good source of food for bacteria which increase rapidly, depleting the oxygen dissolved in the water (as they respire aerobically) and causes death of aquatic organisms such as fish- known as eutrophication
46
What is the effect of chemical waste on the environment?
many heavy metals and other chemicals are persistent- they do not break down and so can build up in food chains (known as bioaccumulation), poisoning the top carnivores
47
What is the effect of discarded rubbish on the environment?
much rubbish, such as that made from plastic, is non-biodegradable and remains in the environment for hundreds of years. animals also eat the plastic as it breaks into smaller pieces (especially in the ocean) and it can get into food chains this way
48
What is the effect of fertilisers on the environment?
causes algal blooms which then die and provide a good source of food for decomposing bacteria which increase rapidly, depleting the oxygen dissolved in the water as they respire aerobically) and causing death of aquatic organisms such as fish known as eutrophication
49
What is the effect of insecticides and herbicides on the environment?
bioaccumulation, loss of biodiversity, damage to beneficial insects. can build up in soil to toxic concentrations and harm other organisms
50
What is the effect of nuclear fallout on the environment?
some radioactive particles have long half-lives and can remain in the environment for many years. they can cause increased risks of cancer and smaller particles can be carried by winds hundreds of miles from the original site of exposure
51
What is the effect of methane on the environment?
methane is a greenhouse gas which contributes to the enhanced greenhouse effect that is causing climate change
52
What is the effect of carbon dioxide on the environment?
carbon dioxide is a greenhouse gas which contributes to the enhanced greenhouse effect that is causing climate change
53
Why do plastics have such a negative impact on the environment?
Plastics have a large negative impact on both land and water habitats due to their non-biodegradability
54
1. What effects does plastic have on animals in marine habitats?
Animals often try to eat plastic or become caught in it, leading to injuries and death
55
2. What can plastic release as it breaks down?
As the plastic breaks down it can release toxins that affect marine organisms
56
3. How can plastic enter the food chain?
Once it has broken down into very small particles, it is commonly ingested by animals and enters the food chain
57
How is plastic usually disposed of?
Plastic is generally disposed of by burying in landfills
58
Why is it harmful to dump plastic in landfills?
As it breaks down, it releases toxins into the surrounding soil and as such the land is no good for growing crops or grazing animals and can only be used for building on several decades after burial
59
What chemical substance can be harmful if it reaches a water supply?
Female contraceptive hormones are excreted from the body in urine and then make their way into the water supply, as they are not filtered out by sewage treatment plants
60
What can female contraceptive hormones cause, in aquatic environments?
If they reach male aquatic organisms, such as fish and frogs, which are very sensitive to the hormones, it causes feminisation
61
What is feminisation?
This is where male organisms begin to produce eggs and lose the ability to reproduce
62
Why is feminisation harmful to aquatic organisms?
Consequently, a smaller amount of offspring is produced which can harm the species survival and also disrupts food chains for animals that usually feed off these organisms
63
How can feminisation be harmful to humans?
In addition, these hormones can reduce the sperm count in human males, which causes fertility problems
64
1. What is the first stage of eutrophication? What goes where and what does this cause?
Runoff of fertiliser from farmland enters the water and causes increased growth of algae and water plants
65
2. Why is algal bloom harmful?
eutrophication
The resulting ‘algal bloom’ blocks sunlight so water plants on the bottom start to die, as does the algae when competition for nutrients becomes too intense
66
3. What can happen when lots of aquatic organisms die at once, as a result of eutrophication?
eutrophication
As water plants and algae die in greater numbers, decomposing bacteria increase in number and use up the dissolved oxygen whilst respiring aerobically
67
4. What may be a result of a large amount of bacteria respiring aerobically in a pond?
eutrophication
As a result there is less oxygen dissolved in water, so aquatic organisms such as fish and insects may be unable to survive
68
What creates sulfur dioxide?
Combustion of fossil fuels that contain sulfur impurities creates sulfur dioxide
69
How is sulfur trioxide created?
Sulfur dioxide is released into the atmosphere where it combines with oxygen to form sulfur trioxide
70
What forms acid rain?
Sulfur trioxide dissolves in water droplets in clouds and forms acid rain
71
What gases can cause acid rain?
sulphur dioxide
- oxides of nitrogen
72
What release sulphur dioxides and oxides of nitrogen into the air?
burning of fossil fuels
- combustion of petrol in car engines
73
What are 5 effects of acid rain?
Damage to leaves, killing plants
Acidification of lakes, killing animals
Increased risk of asthma attacks and bronchitis in humans
corrosion of stonework on buildings
release of aluminium from the soil into lakes that are toxic to fish
74
What are 3 possible solutions for acid rain?
changing the power stations from coal and oil to renewable energy sources
using ‘scrubbers’ in power station chimneys to remove sulphur dioxide
using catalytic converters in car exhausts to convert oxides of nitrogen to harmless nitrogen
75
What is a greenhouse gas?
A greenhouse gas is a gas that absorbs infrared radiation from the Sun so it remains trapped in the Earth’s atmosphere
76
Why are greenhouse gases important?
This is important to ensure Earth is warm enough for life
77
Why are high levels of greenhouse gases dangerous?
however if levels of these gases in the atmosphere increase it leads to an increase in the greenhouse effect which causes the Earth’s average temperature to rise
78
What are 5 examples of greenhouse gases?
Water vapour
Carbon dioxide
Methane
Nitrous oxides
CFCs
79
1. What is emitted from where that enters the earth’s atmosphere?
(greenhouse effect)
The Sun emits rays that enters the Earth’s atmosphere
80
2. What happens to the suns rays once they enter the earth’s surface? (3 options)
(greenhouse effect)
The heat bounces back from the Earth’s surface
Some heat is reflected back out into space
Some heat is absorbed by greenhouse gases and is trapped within the Earth’s atmosphere – this is normal
81
3. What can the greenhouse effect cause and how?
However, as the levels of greenhouse gases in the atmosphere rise due to human activities the Earth’s average temperature rises beyond normal (an enhanced greenhouse effect), causing global warming or climate change
82
What are 6 consequences of global warming due to an enhanced greenhouse effect? (brief)
ocean temperatures increase
extreme weather
loss of habitats
decrease in biodiversity
increase in migration of species
spread of pests and disease
83
Why is it bad if ocean temperatures increase?
Ocean temperatures increase which causes melting of polar ice caps / rising sea levels / flooding / coral bleaching
84
What causes extreme weather and what are examples?
Increasing temperatures can cause extreme weather like super storms, flooding, droughts
85
What can extreme weather events cause?
These extreme weather events can lead to changes in or loss of habitats
86
How can global warming lead to a decrease in biodiversity?
This means that there will be a decrease in biodiversity as food chains are disrupted and extinction rates increase
87
What is a sustainable resource?
A sustainable resource is one which is produced as rapidly as it is removed from the environment so that it does not run out
88
What are examples of non-renewable resources and why?
Some resources, such as fossil fuels (coal, oil and natural gas), are non-renewable because what we use cannot be replaced
89
What do we need to do in order not to run out of fossil fuels?
These resources, once used, cannot be produced anymore and so they need to be conserved by reducing the amount we use and finding other, sustainable resources to replace them
90
How are fossil fuels used? 2
Fossil fuels are being used as an energy source in increasing amounts
In addition, they are the raw materials for many other products we make
91
What substances are made from fossil fuels?
almost all plastics that are made start with oil as a raw material
92
What substances can be reused and recycled?
Some products, especially those made from paper, plastic, glass or metal, can be reused and recycled
93
Why is reusing and recycling substances good?
this reduces waste in the environment and reduces the amounts of raw materials and energy needed to make new products
94
What resources can be maintained and how does this help with sustainability?
Some resources, such as forests and fish stocks, can be maintained – enabling us to harvest them sustainably so that they will not run out in the future
95
What is sustainable development?
Sustainable development is defined as development providing for the needs of an increasing human population without harming the environment
96
What is the problem with sustainable development?
When developing the way in which we use resources to manage them sustainably, we have to balance conflicting demands
97
What 3 conflicting aspects need to be taken into account when trying to develop sustainably?
needs of local people vs large companies
needs of Human Resources vs needs of animals and plants
needs of the current and future population
98
What are the conflicting demands of local people vs large companies?
the need for local people to be able to utilise the resources they have in their immediate environment with the needs of large companies to make money from resources such as forests and fish
99
What are the conflicting demands of Human Resources vs animals and plants?
the need for balancing the needs of humans for resources with the needs of the animals and plants that live in the areas the resources are taken from (preventing loss of habitat and extinction)
100
What are the conflicting demands of current vs future population?
for example if we harvest all the fish we need to feed people now, this might lead to overfishing which would deplete stocks for future generations
101
What is very important for development to occur sustainably?
For development to occur sustainably, people need to cooperate at local, national and international levels in the planning and management of resources
102
What supplies can forests provide? 2
Forests are needed to produce paper products and provide wood for timber
103
Where is most of the world’s paper produced?
Much of the world’s paper is now produced from forests which replant similar trees when mature trees are cut, ensuring that there will be adequate supply in the future
104
What types of wood takes a long time to grow and why are they so desirable?
Tropical hardwoods such as teak and mahogany take many years to regrow but are highly desirable for furniture
105
How has using growing wood for timber become more sustainable? (industrial)
Using these types of wood has now been made more sustainable due to the introduction of several schemes designed to monitor logging companies and track the wood produced (eg the Forestry Stewardship Council)
106
How has using growing wood for timber become more sustainable? (societal)
Education helps to ensure logging companies are aware of sustainable practices and consumers are aware of the importance of buying products made from sustainable sources
107
What 3 factors need to be controlled in order to control fish stocks sustainably?
Controlling the number of fish caught each year (quotas)
Controlling the size of fish caught
Controlling the time of year that certain fish can be caught
108
Why does the size of fish caught need to be monitored?
to ensure there are enough fish of a suitable age for breeding remaining
109
Why does the time of year the fish are caught need to be monitored?
to prevent large scale depletion of stocks when fish come together in large numbers in certain areas to breed
110
What 2 other factors are important in order to control fish stocks sustainability?
restocking
- educating fisherman
111
How does restocking help to sustain fish stocks?
breeding and keeping offspring until they are large enough to survive in their natural habitat then releasing
112
How does educating fishermen help to sustain fish stocks?
Educating fishermen as to local and international laws and consumers so they are aware of types of fish which are not produced sustainably and can avoid them when buying fish
113
1. What does the demand increase for as the human population increases?
sewage
As human population grows, the need for fresh water increases
114
2. Where does a significant amount of water we consume go?
sewage
A significant amount of water we consume is used to flush away human waste (sewage) into pipes
115
3. Where do the pipes carry the sewage to?
sewage
The pipes carry the sewage and water to treatment plants
116
4. What happens in treatment plants?
sewage
the organic waste is removed and the water cleaned so it can be returned to natural water sources without causing eutrophication
117
5. Where is crude sewage passed through and what does this do?
sewage
Crude sewage flows through a screen in which large materials like paper and sticks are trapped so they can be removed and burned
118
6. Where is the sewage passed though after screening?
sewage
The sewage is passed slowly through channels where grit and other heavy particles picked up along the way settle to the bottom
119
7. What happens to the grit that settles along the bottom of the channel?
sewage
the grit is later washed and returned to the land
120
8. Where do the channels lead to?
sewage
The channels lead into sedimentation tanks
121
9. What happens in sedimentation tanks?
sewage
the solid material settles on the bottom as sludge and the liquid part, called effluent, remains on top
122
10. What happens to the sludge?
sewage
The sludge is removed by pumping it into tanks where anaerobic bacteria decompose it
123
11. What do the bacteria in the tanks produce and what is done with this?
sewage
often the bacteria produce methane which can be collected and used as an energy source for the plant
124
12. What is the effluent treated with? What does this do?
sewage
The effluent (liquid) is treated with aerobic bacteria to remove any organic waste in it
125
13. What is added to the effluent once it is treated with aerobic bacteria? What does this do?
sewage
treated with chlorine to kill the bacteria
126
14. After being treated with chlorine, where does the effluent go?
sewage
At this point it is clean enough to return to natural water systems or be passed on to a second treatment plant where it is processed further to make it pure enough to reuse as drinking water
127
What are endangered species at risk of?
An endangered species is at risk of becoming extinct
128
What does it mean if a species is endangered?
the population of the species may fall below a critical level
129
What 5 factors may cause a species to become endangered?
hunting
climate change
pollution
loss of habitat
introduction of non-native species that outcompete native species
130
What 4 conservation measures can endangered species be helped by?
education programmes
captive breeding programmes
monitoring and legal protection of the species and of their habitats
seed banks
131
What are seed banks? What do they store and why?
seed banks as a conservation measure for plants – seeds of endangered plant species are carefully stored so that new plants may be grown in the future
132
What may cause a species to be at risk of extinction, biologically speaking?
A species may be at risk of becoming extinct if there is not enough genetic variation in the population
133
Why is a lack of genetic variation a cause of extinction?
as random changes in the environment may quickly cause extinction because the remaining organisms are all very similar and may not have the adaptations to survive such changes
134
What is a moral reason for conservation programmes?
reducing extinction rates of both plant and animal species
135
What is a cultural reason for conservation programmes?
keeping damage to food chains and food webs to a minimum and protecting vulnerable ecosystems (eg the rainforests)
136
What is a scientific reason for conservation programmes?
protecting our future food supply and maintaining nutrient cycles and possible sources of future medical drugs and fuels
137
How has modern technology increased food production?
Agriculture machinery- improved efficiency
Chemical fertilisers improve yields
Insecticides and herbicides- reduced competition
Selective Breeding- Reliably made to produce high yields
138
What are the negative impacts of monocultures?
Biodiversity is low
Increase in pest populations
Leads to insecticides being sprayed which kills harmless insects, pollution, pests becoming resistant
139
What is the negative impacts of intensive livestock farming?
Reduction in biodiversity
Overgrazing leads to soil erosion
Large amounts of cattle produce a lot of methane- greenhouse gas
140
What are livestock usually fed?
High energy foods and antibiotics as a presentative measure against disease
141
How can famine occur?
When people do not receive enough food
142
What can cause famines?
Natural disasters- drought and flooding
Increasing population
Poverty
Unequal food distribution
143
Describe the problem of global food supply
More land is needed to grow crops/animals-deforestation-increasing amount of greenhouse gas- global warming- tropical storms and drought-flooding- destruction of habitable food
144
What are the reasons for habitat destruction?
– increased area for food crop growth, livestock
production and housing
– extraction of natural resources
– marine pollution
145
What is deforestation?
The clearing of trees
146
What can be caused by altering food webs and food
chains?
Humans suffer a negative impact
147
What are the undesired effect of deforestation?
Extinction of species
Loss of soil
Flooding
Increase of carbon dioxide in atmosphere
148
Explain how soil erosion can be caused by deforestation
Trees roots stabilise the soil-preventing it from being eroded from rain
Trees take nutrients from the soil and if there weren’t any trees these would wash into lakes
149
State sources of pollution
Industry, manufacturing processes, discarded rubbish, nuclear fall out and untreated sewage
150
Give two examples of greenhouse gases?
Carbon dioxide and methane
151
What do greenhouse gases do?
Contribute to the enhanced greenhouse effect
152
What are the effects of non-biodegradable plastics on the marine?
Animals try to eat plastic leading to injuries and death
Plastic breaks down it releases toxin
Once it breaks down it releases toxins and enters the food chain
153
What are the effects of non-biodegradable plastics on land?
Burying in landfills
It releases toxins and so the surrounding soil is no good for growing crops or grazing animals
154
What is the effect of female contraceptive hormones?
Causes feminisation in males- affects food chains as less reproduce- males sperm count is reduced
155
What creates sulphur dioxide?
Combustion of fuels containing sulphur impurities
156
What are possible solutions to reduce acid rain?
Changing power stations to renewable sources
Using scrubbers to remove sulphur dioxide from factory chimneys
Catalytic converters in car exhausts
157
What are greenhouse gases?
Absorbs infrared radiation from the Sun so it remains trapped in the Earth’s atmosphere
158
What happens to an excess of greenhouse gases?
The Earth’s average temperature rises
159
What are the most important greenhouse gases?
Water vapour
Carbon dioxide
Methane
Nitrous oxides
CFC's
160
What are consequences of global warming?
ocean temperatures increase
extreme weather
changes in loss of habitat
decrease in biodiversity
increase in migration
161
Define sustainable resource
It is produced as rapidly as it is removed from the
environment so that it does not run out
162
Define sustainable development
development providing for the needs of an
increasing human population without harming
the environment
163
What must be taken into consideration when developing a way in which we use resources to manage them sustainably?
The need for local people to be able to utilise the resources they have
The need for balancing hte needs of humans for resources with the needs of animals and plants that live in the area
The need to balance what current populations need with what future populations might need
164
What do we need forests for?
To produce paper
Provide wood for timber
165
What ensures the sustainment of forests?
Monitor logging companies that track wood produced
Education
166
How can you sustain fish stocks?
Controlling the number of fish caught each year
Controlling the size of the fish caught
Controlling the time of the year that certain fish can be caught
Restocking
Educating fishermen
167
What are endangered species at risk of?
Extinction
168
Why may a population of species fall below critical level?
Hunting
Climate change
Pollution
Loss of habitat
Introduction of non-native species
169
How can endangered species be helped?
Education programmes
Captive breeding programmes
Monitoring and legal protection of the species
Seed banks as a conservation for plants
170
What are the reasons for conservational programmes?
Reducing extinction rates of both plant and animal species
Keeping damage to food chains minimal
Protecting vulnerable ecosystems
Protecting our future food supply and maintaining nutrient cycles
171
How humans have increased food production:
agricultural machinery to use larger areas of land and improve efficiency
chemical fertilisers to improve yields
insecticides to improve quality and yield
herbicides to reduce competition with weeds
selective breeding to improve production by crop plants and livestock
172
Disadvantages of monoculture:
loss of biodiversity
outbreaks
extinction of species
disruption of food chain
173
Advantages of monoculture:
higher revenue.
easier to manage.
yields maximization.
specialised production.
increased productivity and
efficiency.
174
Disadvantages of intensive livestock production:
loss of biodiversity ;
deforestation / habitat loss ;
effect of waste (faeces and urine) on, waterways/crops;
disease spreading to, wild populations / humans ;
use of antibiotics and (spread of) antibiotic resistance ;
175
Advantages of intensive livestock production:
help to provide more food for people
sometime provide food more cheaply than extensive systems
fewer people go hungry
take up less land
more land could be left in its natural state, providing habitats for other species
176
Biodiversity
number of different species that live in an area.
177
Reasons for habitat destruction:
increased area for housing, crop plant production and livestock production
extraction of natural resources
freshwater and marine pollution
Through altering food webs and food chains, humans can have a negative impact on
habitats.
178
Effects of deforestation:
habitat destruction
reducing biodiversity
extinction
loss of soil
flooding
increase of carbon dioxide in the atmosphere
179
Effect of pollution and excess fertilisers in aquatic ecosystems:
lake/ river pH decrease
aluminium ions become mobile
nutrients leached
shell damage
fish/ frog fail to reproduce
aquatic plants die
disruption of food chain
loss of biodiversity
Biology notes By Vasumitra Gajbhiye 51
low pH toxic to aquatic animals
fish produce mucus which blocks gills.
180
Effect of plastic on aquatic ecosystem:
plastic remains /persists / lasts a long time/ not decomposed ;
swallowed/ ingested/eaten/ cannot be digested/ blocks gut ;
caught, around/ strangle/trapped/ entangled/ smother/ suffocate / injure/ cut /
trap/ stuck in, organism AW ;
plastic blocks light for, photosynthesis ;
may, contain/release, (oil-soluble) toxins / poisons / harmful chemicals;
blocks the flow of water in streams or rivers ;
so less aeration of water/reduces concentration of (dissolved) oxygen ;
destruction of, habitat/ ecosystem/ food chain ;
idea of bioaccumulation/ biomagnification ;
trapped / stationary water acts as a breeding site for mosquitoes ;
AVP ; e.g. visual pollution /releases hormone-like chemicals / less oxygen from
photosynthesis
181
Effect of plastic on terrestrial ecosystem:
CHOKES/ strangles / traps / blocks digestive systems / AW (of animals)
ingested ;
reference to, chemical exposure / fumes / toxins ;
(plastic) accumulates in an organism / is passed down a food chain ;
(described) habitat destruction ;
e.g. plastic covers the habitats (plastic) blocks (light / water for) photosynthesis
(for land plants) ;
visual pollution ;
(plastic) block roots / prevents root growth ;
remain in the ecosystem (for a very long time) ;
182
green house gases
Methane and carbon dioxide
183
how do greenhouse gasses affect climate
They trap infrared radiation
emitted from the sun towards the earth. This keeps the planet warm enough to
support life. If level of these green house gases rise, more infrared radiation is
trapped, this increase the average temperature of earth. Resulting in enhanced
green house effect, leading to climate change.
184
Eutrophication of water:
increased availability of nitrate and other ions
increased growth of producers
increased decomposition after death of producers
increased aerobic respiration by decomposers
reduction in dissolved oxygen
death of organisms requiring dissolved oxygen in water
185
Sustainable resource
one which is produced as rapidly as it is removed from the
environment so that it does not run out
186
Some resources can be
conserved and managed sustainably, e.g. forests and fish stocks.
187
Why an organism becomes
endangered:
climate change
habitat
destruction
hunting
overharvesting
pollution
introduced species
188
Reasons why a plant species can become endangered species:
plant hunting
disease
lack of pollinators
competition from introduced
species
deforestation
climate change
desertification
pollution
increase in gazing
habitat destruction
removing too many of a plant
species
189
Reasons why a fish
species can become
endangered species.
habitat destruction ;
climate change ;
(described) overfishing
/ hunting ;
food chain disrupted
(described);
overconsumption (by
humans) ;
(named) pollution ;
introduced diseases /
species ;
190
Reasons why a animal species can become
endangered species.
1 habitat loss/deforestation;
2 large mammals need large amounts of space ;
3 (named example of) climate change; e.g.
desertification
191
Use of land for
4 land developed for agriculture ;
5 land developed for, housing / transport /
factories
6 land used for extraction of (named) material(s)
7 competing with humans for space ;
8 idea that populations are isolated ;
9 hunt / trophies / high value / poaching ;
10 laws are not enforced to protect from hunting
11 lack of education ;
12 poisoning / pollution ;
13 need a large quantity of food / lack of food
sources / starvation ;
14 slow reproduction rate / hard to breed in
captivity ;
192
How endangered species can be conserved:
monitoring and protecting species and habitats
education
Biology notes By Vasumitra Gajbhiye 54
captive breeding programmes
seed banks
193
How endangered species can be conserved:
monitoring / AW, population(s) /
individual(s) ;
habitat, protection / restoration ;
reducing / prevention, of pollution;
removal / AW, of alien species ;
preventing colonisation by alien
species ;
hunting ban / prevent poaching ;
government / legislation, to
protect species ;
create, exclusion zones /
reserves (so not disturbed by
people) ;
specific, times when / areas
where, hunting / AW, not allowed
international agreements to limit
trade ;
removal to, zoos / botanical
gardens / wildlife parks ;
captive breeding / breeding
programme (in situ or ex situ) ;
seed banks / frozen zoos /
cryopreservation / AW ;
artificial insemination / IVF / use
of surrogates / AW ;
reintroduction programmes ;
education / awareness ;
194
How can we prevent overfishing:
1 education / awareness ; Accept
commercials / advertising / tax
consumer
2 reduced demand (to eat from
unsustainable fish stocks) / public
pressure / campaigning ;
3 steps taken by fisherman voluntarily
/ AW ;
4 (legal) quotas / treaties / licenses /
laws / restricted catch weight ;
5 ensuring sustainable population
size / recovery of, endangered /
specific, species
6 nursery zones (using this is
much safer)/ no-catch zones / /
protected areas / MPAs ;
7 overflow of target species / increase
in population outside zone / breeding
recovery ;
8 limited fishing season ;
9 stock recovery / optimises breeding
seasons ;
10 fines;
11 discourage / punish, poor practice
12 restocking / captive breeding and
release ;
13 increases gene pool / number of
young / reproductively-viable, fish ;
14 fish farming ;
15 alternative source of fish
195
Reasons for conserve animals
maintains natural habitat/
prevent, human
interference/ development
prevention of extinction
less, hunting/ poaching/
killing
tourism/ economic reason
maintain (bio)diversity/
genetic diversity
maintain, gene,
pool/diversity
maintain, food chain/
balanced ecosystems
available for scientific study
retain for future generations
maintain nutrient recycling
maintain, resource
provision/ food/ drugs
prevent soil erosion/
flooding
education
196
Reasons to maintain ecosystems like
wetlands
to prevent extinction;
maintain biodiversity;
provide feeding grounds for animals /
ref. to disruption of food, chains / web;
provide, breeding grounds / places for
breeding;
provide, habitats / shelter;
vulnerable to the effects of,
development / drainage / AW;
ref to flooding / natural disasters;
ref to nitrogen cycle;
ref to maintenance of water cycle;
ref to carbon cycle; e.g. greenhouse
gas / carbon storage / carbon sink
waste disposal;
provide, resources / food / fuel / drugs /
raw materials;
idea of areas for, recreation /
(eco)tourism / education;
ethical reasons / aesthetic reasons /
AW;
AVP; e.g. soil erosion
197
Artificial insemination:
collect semen / sperm (implied by
context) ;
freeze semen / sperm, / use
sperm bank / use sperm
collected, far away/ long ago ;
selecting / washing / screening, of
sperm / AW ;
use fertility drugs containing
hormones for (super)ovulation ;
determine when female is about
to ovulate ;
insert, semen / sperm, into
female (vagina / uterus) ;
198
The risks to a plant species of
having very small numbers:
high risk of extinction
less reproduction
high risk of genetic disease
less variation
small population so more
vulnerable to diseases.
reduced number of alleles
less likely to adapt to change in
environment
199
In vitro fertilisation (IVF):
collect / extract, eggs ;
collect / extract, sperm ;
use of donor, eggs / sperm ;
fertilisation / described / IVF,
outside the body / in a dish / in a
laboratory ;
embryo development in dish / AW
screening of embryos ;
inserting embryos into uterus ;
give mother progesterone after
inserting embryos (to maintain
lining) ;
200
food supply
once agriculture had been developed, it was possible to support a much larger population and the balance between humans and the environment was upset.
exponential growth of human population increased the demand for food supply
201
to provide food
trees were cut down for agricultural land and to provide shelter for the increased human population.
intensification of agriculture included the use of insecticides, pesticides, herbicides, and monoculture
areas cleared for intensive livestock farming
use of machinery, artificial fertilizers to increase yield
selective breeding to improve the production of crop and livestock
202
increase in demand for food production caused:
a) deforestation: has a direct impact on climate change
b) wild habits were destroyed affecting climate
c) use of chemical fertilizers resulted in water pollution- eutrophication
203
undesirable effects of deforestation
1)habitat destruction
- species extinction through habitat loss
- suction in habitat or food source for animals can result in their extinction
- loss of forest habitat also reduces biodiversity and disrupts the food chain
2) loss of soil by soil erosion
- removal of trees means there are no roots to hold the soil, thus the thin fertile top layer of the soil is washed by rain or blown by the wind resulting in soil erosion
- land becomes unsuitable for plant growth: desertification
3) flooding
- soil from erosion is washed into the river, silting it and causing flooding
- there are no trees to take up the water, which flows into the rivers causing a flood
3) carbon dioxide build up- global warming
- forests have a high rate of photosynthesis so absorb large amounts of carbon dioxide from the atmosphere
- removal of forests contributes to increase in atmospheric carbon dioxide
204
deforestation threatens many species of animals and plants with
extinction
205
loss of plant species due to deforestation will result in
a loss of animal species of the same community because of their feeding relationships in the food web
206
loss of many trees can also affect the
water cycle
207
deforestation also affects the concentration of
CO2 in the atmosphere
208
the forests take CO2 in the air to use in photosynthesis and return
oxygen to the air
209
whenever the trees are cut down there are
fewer plants to remove CO2
210
moreover, as the cut-down trees decay or burn
the carbon in their bodies is converted into CO2 and released into the air
211
famine
food shortage for the poor
212
cash crop example
cotton
213
cause of severe food shortage/famine
flooding, deforestation, economy of the nation
214
problems of the world food supply
severe food shortage can lead to famine
transportation of foods needs the use of preservatives: food becomes expensive
picking natural products before it is ripe, and exposing them to chemicals to bring on the ripening process
climate change and natural disasters like floods may cause loss of farmland: most farm products are destroyed
pollution
shortage of water
poor soil- the result of monoculture
lack of money to buy seeds
no food production
raid urbanization
increase in human population
pest damage or disease
use of farmland to grow crops or plants for biofuels
215
urbanization
when a village turns into modern buildings/towns/cities
216
biofuels example
sugar cane
217
negative impacts of large-scale monoculture of crop plants
monoculture- growing of single species of plant on the same land year after year affected by the fertility and the balance of the soil- need for artificial fertilizers increases. in a monoculture, every attempt is made to destroy organisms that feed on, compete with or infect the crop plant - use of insecticide, pesticides, and herbicides. so, the balanced life of a natural plant and animal community is displaced- habitat destroyed ( loss of biodiversity)
218
the negative impacts of intensive livestock production
intensive livestock production is also known as “factory farming where water forms slurry which gets into rivers and streams resulting in eutrophication. overgrazing of certain areas resulted in soil erosion and finally desertification. cattle farming increases the production of methane which adds to global warming.
219
how does overuse of fertilizers lead to eutrophication
a) fertilizers with nitrates/ phosphates leach into rivers and lakes after rain- leaching
b) surface water plants and phytoplankton(algae) grow more than usual algal bloom
c)they block sunlight and kill plants underneath that stink to the bottom.
d)aerobic bacteria/fungi decompose the remains of these plants using oxygen and decreasing the oxygen concentration
e) fish and other creatures die from oxygen starvation
f) anaerobic bacteria act upon these dead and decomposing materials of which the end products can be methane or other toxic substances
g) hence the water bodies become unsuitable to support any life
220
increase in human population is the main cause for
habitat destruction
221
removal of habitat for
increased area for food crop growth and livestock production.building housing complexs for shelters.
222
extraction of natural resources for
need of fuel for transportation, factories and urbanization
223
marine pollution
dumping of human debris, and untreated sewage, the problem for many marine animals and their population decreasing due to destruction of habitat.
224
greenhouse effect
completely natural processes where gases in the atmosphere trap heat from the sun. the gases act like the glass in a greenhouse- they let heat in but prevent some of it from getting back out. greenhouse gases are essential to keep the Earth warm, without them, most the plant would be a wasteland.
225
global warming
increase in world temperature as a result of increase in greenhouse gases in the atmosphere
226
greenhouse gases
carbon dioxide, methane, CFCs and nitrous oxide
227
global warming causes
1) burning of fossil fuels. example. coal, oil, and natural gas for industry and transport and heat our homes
2) clearing rainforests ( which act as carbon sinks to naturally absorb excess carbon dioxide from the atmosphere)
3) farming(particularly cattle farming, which generates methane as the greenhouse gases in the atmosphere increases we are getting an enhanced greenhouse effect( the greenhouse effect is more strongly). this is leading to an increase in the average temperatures around the world- global warming, as a result, more people, believe that the climate is changing because of human activity
228
vector
carrier disease
229
artic animals
polar bears
230
antarctic animals
penguins
231
effects of global warming
increase in sea levels
increase in the intensity of extreme weather events
significant changes in the amount and pattern of precipitation
-modifications of trade routes
glacier retreat
mass species extinction
increase in the range of disease vectors
232
insecticides and pesticides used
remains in the environment and enters the food chain where it accumulates as the trophic level increases- bioaccumulation(biomagnification) resulting in loss of biodiversity
233
herbicides used
leach from farmland into water systems such as rivers and lakes, where they can kill aquatic plants, removing the producers from the food chain. animals migrate or get extinct
234
nuclear fallout
this can be the result of a leak from a nuclear power station, or from a nuclear explosion. the radioactive material accumulates into food chains and cnan cause cancer in top carnivores and genetic mutations
235
sources and effects of pollution on the water by chemical wastes
chemicals from factories are released into rivers. they poison the animals and plants and could poison humans who drink the water- a loss of biodiversity
236
sources and effects of pollution on the water by discarded rubbish
decrease the area of habitation and increase competition among species resulting in migration or extinction
237
sources and effects of pollution on the water by untreated sewage and fertilizers
results in eutrophication, habitat destruction, and loss of biodiversity
238
terrestrial
land
239
aquatic
water
240
effects of non-biodegradable Plastics on the Environment
1) in an aquatic ecosystem
- as the plastics in the water gradually deteriorate, they fragment into tiny pieces which are eaten by fish and birds, making them very ill. disrupting of the food chain and loss of biodiversity
2) in terrestrial ecosystem
-takes up valuable space required for animals and also causes visual pollution
241
causes of acid rain
caused by sulfur dioxide (released from the burning of oil and coil, for example in power stations) and nitrogen oxides (present in car exhausts).
242
effects of acid rain
-acid rain harms fish and trees, but it also makes chemical weathering happen more quickly. buildings and statues made from rock were damaged as a result
- acid rain can be extremely harmful to the forest. acid rain that seeps into the group d can dissolve nutrients, such as magnesium and calcium, that trees need to survive
243
negative impacts of female contraceptive hormones
when women use a contraceptive pill, the hormones in it( estrogen or progesterone) are excreted in urine and become present in sewage. the processes of sewage treatment do not extract the hormones so they end up in water systems such as rivers, lakes, and the sea. causing feminization of aquatic animals (fish or amphibians). reduces sperm count in men, causing a reduction in fertility.
pollution/: chemical wastes and sewage in rivers make the water nonpotable, and eutrophication can occur. sulfur dioxide lowers the PH increasing the acidity of the lakes
244
impurities of sewage
carbohydrates, proteins, and fats
245
cephalo
head
246
renal
kidney
247
hepatic
liver
248
gills
organs for gaseous exchnage
249
simple eye
one lens
250
compound lens
many lens
251
Blood clotting prevents
continued / significant blood loss from wounds Scab formation seals the wound with an insoluble patch that prevents entry of microorganisms that could cause infection It remains in place until new skin has grown underneath it, sealing the skin again
252
Poikilothermic
Those which cannot maintain their body temperature and rely on the environment
253
why do pressures change in arteries
arteries receive blood from the contraction and relaxation of strong muscles in the heart
254
pulmonary circuit
heart to lungs
255
systematic circuit
blood to body
256
starch is a __ and __ molecule
big, complex
257
starch cant
diffuse through most substances
258
starch digested by amylase gives
maltose
259
maltose is a __ molecule
simple
260
maltose can
diffuse through most substances
261
enzyme: pepsin
substrate: protein
product: amino acids
262
enzyme: lipase
substrate: fats
product: fatty acids and glycerol
263
enzyme: trypsin
substrate: protein
product: amino acids
264
enzyme: maltase
substrate: maltose
product : glucose
265
plants are divided into two groups
1) ferns
2) flowering plants
266
flowering plants are divided into 2
1) monocotyledons
2)dicotyledons
267
Disadvantages of cross pollination
-not always certain as pollinating agent is always required, and it may or may not be available at a suitable time.
-pollen grains have to be produced in abundance to ensure chances of pollination
-results in a lot of waste in pollen
268
disadvantages of genetically modifying crops
will have less nutritional value. cosumers may reject geneticallt modifed crops as genes are lost and there will no variation
269
a tissue culture is a form of
asexual reproduction
270
reasons why bacteria are useful for genetic modification
rapid reproduction rate
no ethical concerns
bacteria have same bases as DNA
271
names of 2 effectors that contract and relax during pupil reflex
circular muscles and radial muscles
272
why are the eye considered a sense organ
retina tissue also has cone and rod cells present to detect the light stimulus
273
How humans have increased food production:
agricultural machinery to use larger areas of land and improve efficiency
chemical fertilisers to improve yields
insecticides to improve quality and yield
herbicides to reduce competition with weeds
selective breeding to improve production by crop plants and livestock
274
Disadvantages of monoculture:
loss of biodiversity
outbreaks
extinction of species
disruption of food chain
275
Advantages of monoculture:
higher revenue.
easier to manage.
yields maximization.
specialised production.
increased productivity and
efficiency.
276
Disadvantages of intensive livestock production:
loss of biodiversity ;
deforestation / habitat loss ;
effect of waste (faeces and urine) on, waterways/crops;
disease spreading to, wild populations / humans ;
use of antibiotics and (spread of) antibiotic resistance ;
277
Advantages of intensive livestock production:
help to provide more food for people
sometime provide food more cheaply than extensive systems
fewer people go hungry
take up less land
more land could be left in its natural state, providing habitats for other species
278
Biodiversity
number of different species that live in an area.
279
Reasons for habitat destruction:
increased area for housing, crop plant production and livestock production
extraction of natural resources
freshwater and marine pollution
Through altering food webs and food chains, humans can have a negative impact on
habitats.
280
Effects of deforestation:
habitat destruction
reducing biodiversity
extinction
loss of soil
flooding
increase of carbon dioxide in the atmosphere
281
Effect of pollution and excess fertilisers in aquatic ecosystems:
lake/ river pH decrease
aluminium ions become mobile
nutrients leached
shell damage
fish/ frog fail to reproduce
aquatic plants die
disruption of food chain
loss of biodiversity
Biology notes By Vasumitra Gajbhiye 51
low pH toxic to aquatic animals
fish produce mucus which blocks gills.
282
Effect of plastic on aquatic ecosystem:
plastic remains /persists / lasts a long time/ not decomposed ;
swallowed/ ingested/eaten/ cannot be digested/ blocks gut ;
caught, around/ strangle/trapped/ entangled/ smother/ suffocate / injure/ cut /
trap/ stuck in, organism AW ;
plastic blocks light for, photosynthesis ;
may, contain/release, (oil-soluble) toxins / poisons / harmful chemicals;
blocks the flow of water in streams or rivers ;
so less aeration of water/reduces concentration of (dissolved) oxygen ;
destruction of, habitat/ ecosystem/ food chain ;
idea of bioaccumulation/ biomagnification ;
trapped / stationary water acts as a breeding site for mosquitoes ;
AVP ; e.g. visual pollution /releases hormone-like chemicals / less oxygen from
photosynthesis
283
Effect of plastic on terrestrial ecosystem:
CHOKES/ strangles / traps / blocks digestive systems / AW (of animals)
ingested ;
reference to, chemical exposure / fumes / toxins ;
(plastic) accumulates in an organism / is passed down a food chain ;
(described) habitat destruction ;
e.g. plastic covers the habitats (plastic) blocks (light / water for) photosynthesis
(for land plants) ;
visual pollution ;
(plastic) block roots / prevents root growth ;
remain in the ecosystem (for a very long time) ;
284
green house gases
Methane and carbon dioxide
285
how do greenhouse gasses affect climate
They trap infrared radiation
emitted from the sun towards the earth. This keeps the planet warm enough to
support life. If level of these green house gases rise, more infrared radiation is
trapped, this increase the average temperature of earth. Resulting in enhanced
green house effect, leading to climate change.
286
Eutrophication of water:
increased availability of nitrate and other ions
increased growth of producers
increased decomposition after death of producers
increased aerobic respiration by decomposers
reduction in dissolved oxygen
death of organisms requiring dissolved oxygen in water
287
Sustainable resource
one which is produced as rapidly as it is removed from the
environment so that it does not run out
288
Some resources can be
conserved and managed sustainably, e.g. forests and fish stocks.
289
Why an organism becomes
endangered:
climate change
habitat
destruction
hunting
overharvesting
pollution
introduced species
290
Reasons why a plant species can become endangered species:
plant hunting
disease
lack of pollinators
competition from introduced
species
deforestation
climate change
desertification
pollution
increase in gazing
habitat destruction
removing too many of a plant
species
291
Reasons why a fish
species can become
endangered species.
habitat destruction ;
climate change ;
(described) overfishing
/ hunting ;
food chain disrupted
(described);
overconsumption (by
humans) ;
(named) pollution ;
introduced diseases /
species ;
292
Reasons why a animal species can become
endangered species.
1 habitat loss/deforestation;
2 large mammals need large amounts of space ;
3 (named example of) climate change; e.g.
desertification
293
Use of land for
4 land developed for agriculture ;
5 land developed for, housing / transport /
factories
6 land used for extraction of (named) material(s)
7 competing with humans for space ;
8 idea that populations are isolated ;
9 hunt / trophies / high value / poaching ;
10 laws are not enforced to protect from hunting
11 lack of education ;
12 poisoning / pollution ;
13 need a large quantity of food / lack of food
sources / starvation ;
14 slow reproduction rate / hard to breed in
captivity ;
294
How endangered species can be conserved:
monitoring and protecting species and habitats
education
Biology notes By Vasumitra Gajbhiye 54
captive breeding programmes
seed banks
295
How endangered species can be conserved:
monitoring / AW, population(s) /
individual(s) ;
habitat, protection / restoration ;
reducing / prevention, of pollution
;
removal / AW, of alien species ;
preventing colonisation by alien
species ;
hunting ban / prevent poaching ;
government / legislation, to
protect species ;
create, exclusion zones /
reserves (so not disturbed by
people) ;
specific, times when / areas
where, hunting / AW, not allowed
international agreements to limit
trade ;
removal to, zoos / botanical
gardens / wildlife parks ;
captive breeding / breeding
programme (in situ or ex situ) ;
seed banks / frozen zoos /
cryopreservation / AW ;
artificial insemination / IVF / use
of surrogates / AW ;
reintroduction programmes ;
education / awareness ;
296
Reasons for conserve animals
maintains natural habitat/
prevent, human
interference/ development
prevention of extinction
less, hunting/ poaching/
killing
tourism/ economic reason
maintain (bio)diversity/
genetic diversity
maintain, gene,
pool/diversity
maintain, food chain/
balanced ecosystems
available for scientific study
retain for future generations
maintain nutrient recycling
maintain, resource
provision/ food/ drugs
prevent soil erosion/
flooding
education
296
How can we prevent overfishing:
1 education / awareness ; Accept
commercials / advertising / tax
consumer
2 reduced demand (to eat from
unsustainable fish stocks) / public
pressure / campaigning ;
3 steps taken by fisherman voluntarily
/ AW ;
4 (legal) quotas / treaties / licenses /
laws / restricted catch weight ;
5 ensuring sustainable population
size / recovery of, endangered /
specific, species
6 nursery zones (using this is
much safer)/ no-catch zones / /
protected areas / MPAs ;
7 overflow of target species / increase
in population outside zone / breeding
recovery ;
8 limited fishing season ;
9 stock recovery / optimises breeding
seasons ;
10 fines;
11 discourage / punish, poor practice
12 restocking / captive breeding and
release ;
13 increases gene pool / number of
young / reproductively-viable, fish ;
14 fish farming ;
15 alternative source of fish
297
Reasons to maintain ecosystems like
wetlands
to prevent extinction;
maintain biodiversity;
provide feeding grounds for animals /
ref. to disruption of food, chains / web;
provide, breeding grounds / places for
breeding;
provide, habitats / shelter;
vulnerable to the effects of,
development / drainage / AW;
ref to flooding / natural disasters;
ref to nitrogen cycle;
ref to maintenance of water cycle;
ref to carbon cycle; e.g. greenhouse
gas / carbon storage / carbon sink
waste disposal;
provide, resources / food / fuel / drugs /
raw materials;
idea of areas for, recreation /
(eco)tourism / education;
ethical reasons / aesthetic reasons /
AW;
AVP; e.g. soil erosion
298
Artificial insemination:
collect semen / sperm (implied by
context) ;
freeze semen / sperm, / use
sperm bank / use sperm
collected, far away/ long ago ;
selecting / washing / screening, of
sperm / AW ;
use fertility drugs containing
hormones for (super)ovulation ;
determine when female is about
to ovulate ;
insert, semen / sperm, into
female (vagina / uterus) ;
299
The risks to a plant species of
having very small numbers:
high risk of extinction
less reproduction
high risk of genetic disease
less variation
small population so more
vulnerable to diseases.
reduced number of alleles
less likely to adapt to change in
environment
300
In vitro fertilisation (IVF):
collect / extract, eggs ;
collect / extract, sperm ;
use of donor, eggs / sperm ;
fertilisation / described / IVF,
outside the body / in a dish / in a
laboratory ;
embryo development in dish / AW
screening of embryos ;
inserting embryos into uterus ;
give mother progesterone after
inserting embryos (to maintain
lining) ;
