4.7 Ecology Flashcards
1
Q
What is biodiversity and why is it important?
A
the variety of all the different species of organisms on earth/within an ecosystem. It is important because it makes sure that species in an ecosystem are stable
2
Q
How does biodiversity make sure an ecosystem is stable?
A
one species isn’t dependent on another for food, shelter, maintenance of the physical environment
3
Q
How is biodiversity reduced?
A
human activities such as waste production, deforestation and global warming
4
Q
Why have humans’ consumption of resources and waste production increased? How does pollution occur?
A
the rapid growth in human population and increased living standards -> humans are using more resources -> more waste is produced -> more pollution
5
Q
How does pollution in water occur?
A
sometimes untreated sewage is accidentally released into streams and rivers, fertilisers from farms. Both cause dissolved oxygen levels to fall, killing aquatic organisms. Finally, sometimes toxic chemicals from factories are released into the river
6
Q
How does pollution in air occur?
A
air pollution, such as burning coal in power station to release acidic gases and smoke/smog
7
Q
How does pollution on land occur?
A
waste in landfills, landfills destroy the habitats of plants and animals. Toxic chemicals can also leach out of landfills and pollute soil or dumped onto the land
8
Q
How does pollution affect biodiversity?
A
pollution kills animals and plants, reducing biodiversity
9
Q
Human activities that reduce the amount of land?
A
building, quarrying, farming and dumping waste (landfills)
10
Q
Why are peat bogs/lands destroyed?
A
to produce cheap compost for gardens and farms to increase food production and is burned to release energy -> reducing the area of this habitat
11
Q
How does the destruction of peat bogs contribute to the greenhouse effect?
A
contains large amounts of dead plant materials (trapped carbon)
Decay is slow as there is not enough oxygen, the decay or burning of peat releases carbon dioxide into the atmosphere -> contributes to climate change
12
Q
Why does large-scale deforestation occur (in tropical areas)?
A
- to provide land for cattle and rice
fields, and to grow crops for biofuels - Biofuels are plant based fuels to burn instead of fossil fuels
13
Q
How does deforestation contribute to climate change?
A
- Increases carbon dioxide because reducing trees means reducing photosynthesis, meaning more carbon dioxide is left in the atmosphere
- Burning trees produces carbon dioxide, releasing smoke that can harm animals
14
Q
How does deforestation affect biodiversity?
A
a habitat (presumably with high biodiversity), has now been destroyed -> reducing biodiversity
15
Q
What is the greenhouse effect and how can it cause global warming?
A
- Greenhouse gases trap energy from the Sun as heat in the atmosphere, increasing the Earth’s temperature
- increase in levels of carbon dioxide (methane, CO2, water vapour)
16
Q
How have greenhouse gases increased?
A
burning fossil fuels releasing carbon dioxide. Levels of methane also increase due to bacteria in paddy fields used to grow rice and by cows passing wind.
17
Q
What is peer review?
A
scientists checking the evidence for climate change to make sure there is no false claims and the research is valid -> reports in the popular media (newspapers) do not go through peer review -> oversimplified, inaccurate or biased info
18
Q
impacts of deforestation and global warming
A
- destruction of many animals’ habitats, releases large amounts of greenhouse gases, reduces biodiversity
- increased sea levels, more severe weather, change of distribution of animals such as insects, increased melting of polar ice sheets/glaciers
reduces habitat -> reduces biodiversity
19
Q
Programmes to maintain biodiversity
1. breeding programmes
A
to stop endangered species becoming extinct, animals are bred in captivity to make sure it survives if species dies out in the wild.
20
Q
Programmes to maintain biodiversity
A
- breeding programmes
- Protection and regeneration of rare habitats, such as coral reefs
- Reintroduction of field margins and hedgerows
- Governments reducing deforestation and carbon dioxide emissions
- Recycling resources instead of dumping waste in landfills
21
Q
Programmes to maintain biodiversity
3. Reintroduction of field margins and hedgerows
A
in agricultural areas where farmers only grow one type of crop. Farmers leave field margins (a strip of land around fields) where wild plants and animals can live. They also plant hedgerows between fields. Hedgerows and field margins provide a wider variety of plants and animals, preserving the biodiversity
22
Q
Programmes to maintain biodiversity
4. Governments reducing deforestation and carbon dioxide emissions:
A
using renewable sources to generate electricity -> reducing global warming
23
Q
Programmes to maintain biodiversity
5. Recycling resources instead of dumping waste in landfills
A
recycling -> less waste in landfills -> fewer habitats are destroyed -> positive effect on biodiversity
24
Q
Conflicts on preserving biodiversity
A
- expensive, such as paying farmers to reintroduce field margins and hedgerows
- damage to people’s income, reducing deforestation is positive for biodiversity, but people in the tree-felling industry could be unemployed
- conflict between preserving biodiversity and food security. Sometimes pests are killed by farmers to protect crops so more food can be produced. In this process, biodiversity is affected.
25
positive human interactions with ecosystems
- maintaining rain forests, ensuring habitats here are not destroyed
- reducing water pollution and monitoring the changes over time
- replanting hedgerows and field margins to provide habitats which were previously destroyed
26
negative human interactions with ecosystems
- production of greenhouse gases leading to global warming
- producing sulfur dioxide in factories, leading to acid rain and affects habitats
- clearing land to build on, reducing the number of habitats
27
what are the biological factors affecting levels of food security?
1. increasing birth rate threatens food security in some countries
2. changing diets in developed countries -> scarce food resources transported around the world
3. new pests and pathogens that affect farming
(pests eat food crops and pathogens cause infectious diseases)
4. environmental changes impacting food production; lack of rain -> widespread famine in some countries
5. cost of agricultural inputs - modern farming requires lots of resources (fertilisers & pesticides & food for livestock). resources become more expensive as population increases -> some countries can't afford -> threatens food security
6. conflicts that affect availability of food and water in some places of the world (war -> farming disrupted and imports of food unavailable -> and reduce the reliable supply of water
28
what is food security?
having enough food to feed a population
29
What are sustainable methods of food production and why is it important?
Sustainable food production is making enough food without using resources faster than they renew
It is important because it means enough food can be made to feed everyone
30
How can the efficiency of food production be improved?
| And why does this work?
by reducing energy transfer from food animals to the environment -> done by limiting movement (of livestock) & controlling temperature of surroundings
This works because less energy used for moving and controlling body temperature -> more energy available for growth -> more food produced
31
what is factory farming
biomass is used to provide energy for respiration and movement
livestock like calves and chickens can be factory farmed, raising them in small temperature controlled sheds -> small means limited chicken movement
being kept in warm conditions and having their movement restricted means less biomass is wasted (reduces energy transfer) compared to free-range chickens - grow more eggs and grow faster
32
ethical objections to factory farming
- animals are so close together -> infectious diseases can spread more easily - treated w/ antibiotics to stop this
- stressed, more likely to fight
ethical - think that animals should be raised in natural conditions and be able to engage in normal behaviour
33
advantages of factory farming
more efficient -> less biomass is wasted by the animals in respiration
giving animals only food with nutrients -> less food is wasted
chickens - eggs are more easily harvested if chickens are inside
34
Explain the importance of maintaining fish stocks at a level where breeding continues
fish stocks in oceans are declining -> important to maintain fish stocks at a level where breeding continues -> or certain species may disappear in some areas, as there is not enough mature fish to breed and commercial fishing for these species won't be available
35
methods that can help to conserve fish stocks
1. setting fishing quotas (on the number of fish that can be caught in each species
reducing the number of fish caught -> remaining fish breed to bring population back to normal levels
2. control of net size -> large enough so smaller immature fish are not caught, so they can develop into adults and reproduce -> again hopefully restoring size of fish stock
36
what is biotechnology?
can be used to feed the population and potentially provide treatments for a number of diseases
37
biotechnology - the fungus Fusarium
mycoprotein is produced by the microorganism Fusarium, which is a fungus.
mycoprotein is a protein-rich food that's suitable for vegetarians.
large amounts of of mycoprotein can be grown in small spaces -> very efficient protein source
The fungus is grown on glucose syrup in aerobic conditions, where the fungus converts the glucose syrup into mycoprotein. The biomass is harvested and purified so it can be consumed.
38
biotechnology - insulin
genetically modified (GM) bacteria produces human insulin, it is harvested and purified to treat people with diabetes
39
biotechnology - genetically modifying crops (GM)
- genetic modification can be used on crops, could be used to provide more food/ to provide food with an improved nutritional value (in places where they lack access to certain vitamins) such as golden rice , which has been GM to molecules the body needs to make Vitamin A. (natural rice lacks these vitamins) (Vitamin A for vision)
- also modifying them to be resistant to pests/extreme weather conditions -> increase yields
40
population
ecosystem
community
- organisms of the same species in a given area
- all the organisms and the habitat
- all the populations of organisms in a given area
41
interdependence
- interdependence describes how organisms in a community depend on other organisms (food, shelter and reproduction - birds need trees for resting)
If one species is removed it can affect the whole community
42
competition
organisms compete for resources to survive ->
plants may compete for light, space, water & mineral ions
animals may compete for space, food, water and mating partners
43
stable community and examples
where all the biotic (living) and the abiotic (non living) factors are in balance -> population sizes remain fairly balanced
tropical rain forests and ancient oak woodlands
44
abiotic factors (non living)
- light intensity -> light is needed for photosynthesis, rate of photosynthesis affects growth of plant
- temperature -> affects rate of photosynthesis
- moisture levels -> p & a need water to survive
- soil pH & mineral content -> soil pH affects rate of decay, and how fast mineral ions return to soil
- wind intensity & direction
- CO2 levels -> affects rate of photosynthesis in plants
- oxygen levels for aquatic animals -> most fish need a high concentration of O2 to survive
45
biotic (living) factors
- food availability -> more food means more organisms can breed more successfully -> population can increase
- new predators arriving
- new pathogens - population has no resistance when a new pathogen rises -> can be wiped out quickly
- competition -> one species outcompeting another so the numbers are no longer sufficient to breed
46
adaptations
| extremophiles
- organisms have features that allow them to survive in the conditions that they live in
- some organisms live in very extreme environments, such as high temperature, pressure or salt concentration
- > bacteria living in deep sea vents
47
structural adaptations
behavioural adaptations
functional adaptations
- shape or colour of an organism -> thick layer of fat, camouflage, sharp teeth
- the way an organism behaves -> playing dead to avoid predators
- in processes such as reproduction & metabolism ->
conservation of water through producing little sweat
48
examples of adaptations in cold climates
smaller surface area to volume ratio to reduce heat loss, lots of insulation such as fur coat and blubber
49
examples of adaptations in dry climates
adaptations to kidneys so they can retain lots of water, resting in shady areas, active in the early morning and evenings when it is cooler
50
examples of adaptations in plants
curled leaves to reduce water loss, waxy cuticle to stop water evaporating, water storing tissue in stem
51
what are the producers of biomass for life on earth?
| how can feeding relationships be shown?
- photosynthetic organisms
| - food chains show feeding relationships and the flow of energy
52
food chains
1. begin with a producer (usually green plant or algae) -> synthesises molecules and makes glucose (biomass) in photosynthesis
producers are the source of all biomass in a community
2. producers are eaten by primary consumers, which are then eaten by secondary consumers, and then tertiary consumers
53
predator - prey cycles
only work in a stable community
| the numbers of predators and prey rise and fall in cycles
54
why are transects and quadrats used?
to work out the distribution and abundance of species in an ecosystem
55
quadrats
only used for plants or slow moving animals such as snails
56
random sampling (quadrats)
- to compare the numbers of organisms in different areas
only used for plants or slow moving animals such as snails
random locations across the area - random numbers
- place the quadrat on the ground and count the number of organisms inside
need to place the quadrat a large number of times to get valid results
random sampling can also estimate the total population size of a species in an area
total population size = total area / area sampled then x number of organisms of species counted in sample
57
sampling along transects (line such as a tape measure or piece of rope)
- how the numbers of organisms change across a habitat
transect runs across the habitat and then use a quadrat to count the number of organisms at intervals (by a set distance) on the transect
again carry out the transect a number of times to get valid results
58
required practical 9 - measure the population size of a common species in a habitat using sampling techniques
estimating the population of daisies in a field using random sampling (quadrats)
1. place two tape measures at right angles
2. use a random number generator to get 2 numbers to work as coordinates to find a location
3. set down the quadrat at these coordinates
4. count and record the number of the required plant species in the quadrat (daisies)
5. repeat steps 2-4 to take 9 more samples (10)
6. estimate the total population size:
total area/area sampled x number of species counted
only an estimate, increase the number of quadrat throws to cover greater percentage of area
59
random sampling
| systematic sampling
- each sample has an equal probability of being chosen
| - where there is a fixed interval between consecutive samples
60
required practical 9 - Use sampling techniques to investigate the effect of a factor on the distribution of this species.
1.Write down a hypothesis of the effect of a change in an abiotic factor -> effect of light intensity on the distribution of daisies
another field of daisies but this one contains a large tree
2. use a transect line to see how the number of daisies changes from the tree outwards
3. use a quadrat to count the number of daisies at the start of the transect, and also record the light intensity using a light meter/app
4. move quadrat 1m down the transect, repeat the measurements
5. repeat this all the way down the tape measure
we will see a greater number of daisies as we move further away from the tree -> because under the tree there is a lower light intensity and plants need light for photosynthesis
tree also absorbs a lot of water and minerals from the soil -> light intensity might not be the only abiotic factor affecting the number of daisies
61
The best temperature for anaerobic digesters is about 35°C.
Explain why the volume of biogas produced would be less at higher temperatures. (2)
Why should biogas not be allowed to escape into the atmosphere?
- enzymes would become denatured and enzyme shape is vital for function
- cause global warming which leads to climate change
62
What are the advantages and disadvantages of buying tomatoes grown in the UK, instead of buying tomatoes grown in the Canary Islands? (3)
- less pollution, less transport
| - production of heat/light causes pollution, not available all year
63
(all sources)
The number of fish in the oceans is decreasing.
The table below shows information about the mass of fish caught by UK fishermen between 2002 and 2010.
Describe the pattern in the table above for the mass of fish caught from all sources.
Suggest reasons for this pattern. (4)
Suggest why the percentage of fish caught from sustainable sources is
increasing. (1)
- Mass of fish declines until 2008 due to increase in fishing. Then rises until 2010 due to fishing quotas/net restrictions working.
- public awareness/demand
64
In a fish farm, large numbers of fish are grown in cages in the sea.
Why do fish in the cages grow faster than fish of the same species that are free in
the sea?
You should refer to energy in your answer. (4)
Fish cannot move as freely, therefore less energy loss, also more food available, so there is more energy for growth.
65
Herring migrate to feed and spawn (lay eggs).
The eggs normally take about 3 weeks to hatch at 12 °C.
If the temperature of the water is higher the eggs will hatch more quickly.
But, if the temperature of the water is above 19 °C, the eggs will die.
Other fish, such as cod, feed on herring.
Suggest how climate change could affect North Sea fish (4)
Increase in sea temperature changes distribution of species. More eggs may survive and could lead to an increase in herring population. Reduction in herring population because eggs die at temperatures greater than 19°C
66
Clearing forests causes some species to become extinct.
(i) What is meant by extinct? (1)
(ii) It is important to prevent species from becoming extinct. Give one reason why. (1)
- none of species left
| - may have products useful to humans
67
Some of the leaves from the gardener’s strawberry plant die.
The dead leaves fall off the strawberry plant onto the ground.
The carbon in the dead leaves is recycled through the carbon cycle.
Explain how the carbon is recycled into the growth of new leaves. (6)
* carbon compounds in dead leaves are broken down by microorganisms
* photosynthesis uses carbon dioxide
* microorganisms respire
* and release the carbon from the leaves as carbon dioxide
* plants take in the carbon dioxide released to use in photosynthesis to produce glucose
* glucose produced in photosynthesis is used to make amino acids & proteins
* (which are) required for the growth of new leaves
68
Explain how the amount of sunlight could affect the distribution of buttercup plants. (3)
light is needed for photosynthesis to make food -> more buttercups in sunny areas
69
The table below shows how the mass of household waste in the UK has changed from 2004 to 2012.
The UK government has been encouraging a ‘zero waste economy’. In a ‘zero waste economy’, we reduce, reuse and recycle as much waste as
possible.
A newspaper concluded that: ‘The government’s ‘zero waste economy’ has been successful.’
Use information from the table to describe the reasons for and against the newspaper’s conclusion.
For :
- there has been a reduction in total waste
- there has been an increase in recycling
Against :
- there is still a lot of waste that hasn't been recycled
- there has only been a small reduction in total waste
70
zwe c) Describe two other possible effects of global warming on our environment (2)
- change in climate
| - change of distribution of species
71
(rp) How could you improve the practical to give a more accurate result?
more quadrats placed randomly
72
People need to eat protein to grow and to be healthy.
Some people think that it would be an advantage to get more food from mycoprotein
and less from farming animals.
Suggest two possible advantages of getting more food from mycoprotein. (2)
1. quicker
| 2. mycoprotein is a protein rich food that is suitable for vegetarians
73
The herring population in the North Sea has changed a lot in recent years.
The graph shows the estimated biomass of herring in the North Sea between 1965 and
2010.
a) Describe the pattern shown in the graph from 1978 to 1983 and suggest why (2)
b) In 1996 the Government brought in strict rules to help to conserve fish stocks. Were the Government’s rules effective?
Use data from the graph to support your answer. (2)
a) increase from 50 to 350 due to fishing ban
| b) was effective at first but numbers decline again after 2004
74
Farmers make more profit from keeping pigs indoors than from keeping pigs
outdoors.
Use information from the pie charts to explain why. (2)
less movement and more growth
75
To produce cheap meat, animals must be grown (reared) efficiently. When pigs are
reared intensively they are kept indoors. Their surroundings are closely monitored to
make sure they have even ventilation and the correct temperature.
a) Explain why farmers control the temperature. (2)
b) Give two arguments against rearing pigs indoors instead of rearing them outdoors. (2)
- less energy wasted in maintaining body temperature and so they don't get too hot or cold
- cruel and increased risk of disease
76
Scientists investigated the growth of two species, A and B, of the fungus Fusarium. The scientists grew the fungus on agar jelly in Petri dishes. They measured the diameter of a colony of each fungus every day for 8 days.
The graph shows the results.
a) Describe how the diameter of the colony of species A changed between day 0
and day 8. (2)
b) When Fusarium is grown in an industrial fermenter, other factors also need to be
controlled. (not temperature or nutrients)
Give two of these other factors.
a) increased, increased slower at the end
| b) oxygen, pH
77
Why is meat from pigs kept inside usually cheaper than meat from pigs kept outside? (1)
faster growth
78
Give two reasons why some people think traditional farming is better than the
cattle factory. (2)
1. less disease
| 2. crops fertilised
79
When fertiliser goes into the river, the concentration of oxygen dissolved in the water decreases.
Explain why the concentration of water decreases.
Fertilisers cause the growth of plants, blocking the light. Low light cause the plants to die. Microorganisms carry out decay and break down dead plant material/organic matter, which they use oxygen for in aerobic respiration.
80
Farm animals give off large amounts of methane.
| Explain the effects of adding large amounts of methane to the atmosphere. (3)
Methane absorbs energy and heat is reradiated leading to global warming.
81
The curry spice coriander works like an antibiotic. Adding coriander to animal food
reduces methane production by about 40%.
(a) (i) Why does adding coriander to an animal’s food reduce methane production? (1)
(ii) Explain one advantage to a farmer of adding coriander to the animal's food. (2)
reduces methane bacteria
less food converted to methane, more growth
82
The diagram shows a fermenter. This fermenter is used for growing the fungus Fusarium.
Fusarium is used to make mycoprotein.
Bubbles of air enter the fermenter at A.
Give two functions of the air bubbles (2)
temperature maintenance and supply oxygen
