T7: ecology Flashcards
1
Q
What is a habitat?
A
The place where an organism lives.
2
Q
What is a population?
A
All the organisms of one species living in a habitat.
3
Q
What is a community?
A
The populations of different species living in a habitat.
4
Q
What are abiotic factors?
A
Non living factors of the environment e.g. temperature
5
Q
What are biotic factors of the environment?
A
Living factors of the environment e.g. food
6
Q
What is an ecosystem?
A
The interaction of a community of living organisms (biotic) with the non living (abiotic) parts of their environment.
7
Q
What do organisms need from their environment and other organisms in order to survive and reproduce?
A
1) plants need light + space as well as water and mineral ions (nutrients) from the soil.
2) Animals need space (territory), food, water and mates.
8
Q
Why do organisms compete with other species (and members of their own species)?
A
Animals often compete with each other for food, mates and territory (for the same resources).
9
Q
What is interdependence?
A
Within a community each species depends on other species for food, shelter, pollination, seed dispersal etc. If one species is removed it can affect the whole community.
10
Q
What is the effect of interdependence of all the living things in an ecosystem?
A
Any major change in the ecosystem (e.g. one species being removed) can have far reaching/ knock on effects.
11
Q
What are stonefly larvae particularly sensitive to?
A
pollution
12
Q
Why is hard to predict the effects of a change in an ecosystem (if one organisms is removed)?
A
Food webs are very complex so it is difficult to predict accurately.
13
Q
What are stable communities?
A
A stable community is one where all the species and environmental factors are in balance so that population sizes remain fairly constant.
14
Q
Give 2 examples of stable communities?
A
- tropical rainforests
- ancient oak woodlands
15
Q
What are the abiotic (non-living) factors which can affect a community .
A
- light intensity
- temperature
- moisture levels
- soil pH and mineral content
- wind intensity and direction
- carbon dioxide levels for plants
- oxygen levels for aquatic animals.
16
Q
How can abiotic factors increase or decrease?
A
A change in the environment.
17
Q
What could changes in abiotic factors caused by the changes in the environment due?
A
- affect the size of population a community
- so they can also affect the population sizes of other organisms that depend on them.
18
Q
What would happen if there was a decrease in light intensity, temperature or level of carbon dioxide?
A
The rate of photosynthesis would decrease in a plant species.
This could affect plant growth and cause a decrease in the population size.
19
Q
What would happen if there was a decrease in the mineral content of the soil (e.g. a lack of nitrates)?
A
- could cause nutrient deficiencies.
- this could also affect plant growth and cause a decrease in the population size.
20
Q
What are the biotic (living) factors which can affect a community?
A
- availability of food
- new predators arriving
- new pathogens
- one species outcompeting another so the numbers are no longer sufficient to breed.
21
Q
How does a change in environment affect biotic factors?
A
could be the introduction of a new biotic factor (e.g. a new predator or pathogen).
22
Q
What could changes in biotic factors caused by the changes in the environment due?
A
These changes can also affect the size of populations in a community, which can have knock on effects because of interdependence.
23
Q
What would happen if there was a new predator?
A
Could cause a decrease in the prey population.
24
Q
What would happen if red a grey squirrels live in the same habitat?
A
- live in same habitat and eat the same food
- grey squirrels outcompete the red squirrels, so the population of red squirrels is decreasing.
25
How are organisms, including microorganisms, able to adapt to live in different environmental conditions?
Organisms have features or characteristics called adaptations that enable them to survive in the conditions in which they normally live.
26
What are the 3 types of adaptations?
structural, behavioural or functional.
27
What are structural adaptations?
These are features of an organism's body structure- such as shape or colour.
28
Give 3 examples of structural adaptations?
- Artic animals have white fur so they're camouflaged against the snow helping them avoid predators and sneak up on prey.
- Animals that live in cold places (whales) have a thick layer of blubber (fat) and a low SA: V ratio to help them retain heat.
- Animals that live in hot places like camels have a thin layer of fat and a large SA:V ratio to help them lose heat.
29
What are behavioural adaptations?
These are ways that the organisms behave. Many species (e.g. swallows) migrate to warmer climates during the winter to avoid the problem of living in cold conditions.
30
What are functional adaptations?
These are things that go on inside the organism's body that can be related to precesses like reproduction and metabolism (all the chemical reactions happening in the body).
31
Give 2 examples of function adaptations?
- Desert animals conserve water by producing very little sweat and small amounts of concentrated urine.
- Brown bears hibernate over winter. They lower their metabolism which conserves energy, so they don't have to hunt when there's not much food about.
32
What are extremophiles?
organisms that are adapted live in environments that are very extreme, such as at:
- high temperature (e.g. super hot volcanic vents)
- pressure (e.g. bacteria living in deep sea vents)
- salt concentration (e.g. very salty lakes)
33
What is the role of photosynthetic organisms?
photosynthetic organisms are the producers of biomass for life on Earth.
34
How can feeding relationships be represented?
Feeding relationships within a community can be represented by food chains.
35
What do food chains start with and what are they and what is the role of this?
producer
- producers make their own food using energy from the sun.
- producers are usually green plants or algae; they make glucose by photosynthesis
36
What happens when a green plant produces glucose?
- some of the glucose is used to make other biological molecules in the plant.
- these biological molecules are the plant's biomass (the mass of living material)
37
What is biomass?
Biomass can be thought as the energy stored in a plant.
38
What happens when organisms eat other organisms?
Energy is transferred through living organisms in an ecosystem when organisms eat other organisms.
39
What is eaten by what in a food chain?
- producers are eaten by primary consumers.
- primary consumers are then eaten by secondary consumers.
- secondary consumers are then eaten by tertiary consumers.
40
What are predators and prey?
Consumers that kill and eat other animals are predators, and those eaten are prey.
41
What usually limits the population of a species?
by the amount of food available
42
What happens do predators + prey in a stable community?
In a stable community the numbers of predators and prey rise and fall in cycles.
43
Explain the cycle of predators and prey in a stable community?
- If the population of the prey increases then so will the population of the predators.
- However, as the population of the predators increase, the population of the prey will decrease.
- Eventually fewer prey will mean fewer predators and they cycle will repeat.
44
Why are predator-prey cycles always out of phase with each other?
It takes a while for one population to respond to changes in the other population.
e.g. when the number of rabbits goes up, the number of foxes doesn't increase immediately as it takes time for them to reproduce.
45
What is the distribution of an organism?
the distribution of an organism is where an organism if sound e.g. in a part of the playing field.
46
What affects where an organisms is found?
- environmental factors
- An organisms might be more common in one area than another due to differences in environmental factors between the two areas.
47
In a playing field, where may you find more daises and why?
in a playing field you may find that daises are more common in the open than under trees, because there's more light available in the open.
48
What are the 2 ways of studying the distribution of an organism?
- measure how common an organism is in 2 sample areas using quadrants and compare them
- study how the distribution changes across an area by placing quadrants along a transect
49
What type of data do both ways of studying the distribution of an organism?
quantity data ( numbers) about the distribution.
50
What is a quadrant and what is it used for?
A square frame enclosing a known area e.g. 1m^2. Used to compare how common an organisms is in 2 sample areas.
51
What are the steps to use quadrants to compare how common an organisms is in 2 sample areas?
1) Place a 1m^2 quadrant on the ground at a random point within the 1st sample area (e.g. divide the area into a grid and use a random number generator to pick coordinates)
2) Count all the organisms within the quadrant.
3) Repeat steps 1 and 2 as many times as possible.
4) Work out the meal number of organisms per quadrant within the first sample area.
5) Repeat steps 1 to 4 in the second sample area.
6) Finally compare the 2 means.
52
How can you work out the population size of an organism in one area using data from quadrants?
1) Work out the mean number of organisms per m^2.
- Then multiply the mean by the total area (in m^2) of the habitat.
53
What are the steps of using a transect to help find out how organisms (like plants) are distributed across an area?
1) Mark out a line in the area you want to study using a tape measure.
2) Then collect data along the line.
3) You can do this by just counting all the organisms you're interested in that touch the line.
4) Or you can collect the data by using quadrants. These can be placed next to each other along the line or at intervals e.g every 2 cm.
54
How can you calculate/ estimate the percentage cover?
1) Count the number of squares covered by the organism.
2) Make this into a percentage: divide the number of squares covered by the organisms by the total number of squares in the quadrant, the x100.
55
What are environmental changes and what do they cause?
- Environmental changes can cause the distribution of organisms to change.
- A change in distribution means a change in where an organisms lives.
56
What are the environmental changes that can affect organisms?
- temperature
- change in the availability of water
- change in the composition of atmospheric gases
57
Give an example of change in availability of water.
The distribution of some animals and plant species in the tropics changes between the wet and dry seasons- i.e. the times of year where there is more or less rainfall and so more or les water available.
E.g each year in America large numbers of giant wildebeest migrate, moving north and then back south as the rainfall patterns change.
58
Give an example of a change in temperature.
The distribution of bird species in Germany is changing because of a rise in average temperature. E.g. the European bee-eater bird is a Mediterranean species but is now present in parts of Germany.
59
Give an example of a change in the composition of atmospheric gases?
The distribution of some species changes in areas where there is more air pollution. E.g. some species of lichen can't grow in areas where sulphur dioxide is given out by certain industrial processes.
60
What may environmental changes be causes by?
The changes may be caused by seasonal factors , geographic factors or caused by human interaction.
61
What is the 1st stage of the water cycle?
Energy from the sun makes water evaporate from the land and sea, turning it into water vapour. Water also evaporates from plants- this is known as transpiration.
62
What is the 2nd stage of the water cycle?
The warm water vapour is carried upward (as warm air rises). When it gets higher up it cools and condenses to form clouds.
63
What is the 3rd stage of the water cycle?
Water falls from the clouds as precipitation (usually rain but sometimes snow or hail) onto land, where it provides fresh water for plants and animals.
64
What is the 4th (last) stage of the water cycle?
It then drains into the sea, before the whole process starts again.
65
What are living things made from?
+ give an example
- made of materials they take from the world around them.
- e.g. plants turn elements like carbon, oxygen, nitrogen and hydrogen from the soil and air into the complex compounds (carbohydrates, proteins and fats) that make up living organisms. These get passed up the food chain.
66
What happens to materials that living things have taken?
These materials are returned to the environment in waste products or when the organisms die and decay.
67
Why do materials decay?
Because they're broken down (digested) by microorganism. This happens faster in moist, warm, aerobic conditions because microorganisms are more active in these conditions.
68
What does decay do?
Puts stuff that plants need to grow (e.g. mineral ions) back into the soil.
69
What happens to materials being cycled in a stable community?
In a stable community, the materials that are taken out of the soil and used by plants etc. are balanced by those that are put back in. There's a constant cycle happening.
70
What are the 8 steps of the carbon cycle?
1) CO2 is removed from the atmosphere by green plants and algae during photosynthesis. The carbon is used to make glucose, which can be turned into carbohydrates, fats and proteins that make up the bodies of the plants and algae.
2) When the plants and algae respire, some carbon is returned to the atmosphere as CO2.
3) When the plants and algae are eaten by animals, some carbon becomes part of the fats and proteins in their bodies. The carbon then moves through the food chain.
4) When the animals respire, some carbon is returned to the atmosphere as CO2.
5) When planets, algae and animals die, other animals ( called detritus feeders) and microorganisms feed on their remains. When these organisms respire, CO2 is returned to the atmosphere.
6) Animals also produce waste that is broken down by detritus feeders and microorganisms.
7) The combustion (burning) of wood and fossil fuels also releases CO2 back into the air.
8) So the carbon (and energy) is constantly being cycled- from the air, through the food chain (via plants, algae, animals and detritus feeders and microorganisms) and eventually back out into the air again.
71
What is compost?
Compost is decaying organic matter that is used as a natural fertiliser for crops and garden plants.
Farmers try to provide the ideal conditions for quick decay to make compost.
72
What do gardeners and farmers try to provide (in terms of compost)?
Gardeners and farmers try to provide optimum conditions for rapid decay of waste biological material. T
73
What is responsible for decomposition (decay)?
Microorganisms like bacteria, fungi as well as detritus feeders.
74
What are the 4 factors that affect the rate of decay?
- temperature
- oxygen availability
- water availability
- number of decay organisms
75
How does temperature affect the rate of decay?
Warmer temperatures make things decompose quicker because they increase the rate that the enzymes involved in decomposition work at.
If it's too hot though, decomposition slows down or stops because the enzymes are destroyed and the organisms die.
Really cold temperatures slow the rate of decomposition too.
76
How does oxygen availability affect the rate of decay?
Many organisms need oxygen to respire, which they need to do to survive. The microorganisms involved in anaerobic decay don't need oxygen though.
77
How does water availability affect the rate of decay?
Decay takes place faster in moist environment because the organisms in decay need water to curry out biological processes.
78
How does number of decay organisms affect the rate of decay?
The more microorganisms and detritus feeders there are, the faster decomposition happens.
79
What is biogas mainly made up of?
Methane, which can be burned as a fuel.
80
How is biogas made?
- lots of different micro-organisms are used to produce biogas.
- They decay plant and animal waste anaerobically
- This type of gas produces methane gas.
81
What can be used to make biogas on a large scale?
Solid sewage sludge from sewage works or sugar factories.
82
What is biogas made in and what are the conditions like?
- in a simple fermentor called a digester or generator.
- biogas generators need to be kept in at a constant temperature to keep the microorganisms respiring.
83
Why does biogas have to be used straight away?
- it can't be stored as a liquid (it needs too high a pressure), so it has to be used straight away: for heating, cooking, lighting or to power a turbine to generate electricity.
84
What are the 2 main types of biogas generators?
Batch generators and continuous generators.
85
What happens in batch generators?
Batch generators make biogas in small batches. They're manually loaded up with waste, which is left to digest, and the by-products are cleared away at the end of each session.
86
What happens in continuous generators?
Continuous generators make biomass all the time. Waste is continuously fed in, and biogas is produced at a steady rate. Continuous generators are more suited to large scale biogas projects.
87
In any simple biogas generator (whether it is continuer or a batch generator) what does it need to have?
1) an inlet for waste material to be put in,
2) an outlet for the digested material to be removed through,
3) an outlet so that the biomass can be piped to where it is needed.
88
What is biodiversity?
Biodiversity is the variety of all the different species of organisms on earth, or within an ecosystem.
89
Why is high biodiversity important?
It makes sure that ecosystems are stable because different species depend on each other for things like shelter and food.
Different species can also help to maintain the right physical environment for each other (e.g. the acidity of the soil)
90
What does the future of the human species on Earth relies?
The future of the human species/ for human species to survive on Earth relies on us maintaining a good level of biodiversity.
91
Why is biodiversity reducing?
Many human activities, including waste production, deforestation and global warming, are reducing biodiversity and only recently have measures been taken to try to stop this reduction.
92
What has happened to the world's population and why?
- The world's population is currently rising very quickly and it's not slowing down.
- This is mostly due to modern medicine and farming methods, which have reduced the number of people dying from disease and hunger.
93
What is the difference now from when the world population was much smaller?
When the world population was much smaller, the effects of human activity were usually small and local. However now, our actions have a far more widespread effect.
94
How does our increasing population put pressure on the environment?
- we take the resources we need to survive.
- People around the world are also demanding a higher standard living ( and so demand luxuries to make life more comfortable- cars, computers, etc).
95
How does the demand for luxuries affect the environment?
So we use more raw materials (e.g. oil to make plastics), but we also use more energy for the manufacturing processes. This all means we're taking more and more resources from the environment more and more quickly.
(raw materials are being used up quickly than they're being made so if we continue like this one day they will run out)
96
Why is more waste being produced?
Rapid growth in the human population and an increase in the standard of living mean that increasingly more resources are used and more waste is produced.
97
What happens if waste, including waste chemicals, are not properly handled?
Unless waste and chemical materials are properly handled, more pollution will be caused.
98
What does pollution affect?
water, land, air and pollution kills plants and animals which can reduce biodiversity.
99
How does pollution affect water?
- Sewage and toil chemicals from industry can pollute lakes, rivers and oceans, affecting the plants and animals that rely on them for survival (including humans)
- The chemicals used on land (e.g. fertilisers, fertilisers and herbicides) can be washed into water.
100
How does pollution affect land?
We use toxic chemicals from industry for farming (e.g. pesticides + herbicides).
We also bury nuclear waste underground and we dump a lot of household waste in landfill sites.
101
How does pollution affect air?
Smoke and acidic gases released into the atmosphere can pollute the air e.g. sulfur dioxide can cause acid rain.
102
What is the temperature of the earth a balance of?
a balance between the energy it gets from the sun and the Energy it radiates back out into space.
103
What do gases in the atmosphere act as?
Act like an insulating layer
104
What increases the temperature of the planet?
Gases in the air absorb most of the energy that would normally be radiated out into space, and re-radiate it in all directions (including back towards the earth.
105
What are green house gases?
several different gases in the atmosphere which help keep the energy in.
106
Which are the main 2 green houses gases that we worry about and why?
The main green house gases whose level we worry about are carbon dioxide and methane because the levels of these 2 gases are rising quite sharply.
107
Why is the earth gradually heating up?
Because of the increasing levels of greenhouse gases- this is global warming.
Global warming is a type of climate change and causes other types of climate change e.g. changing rainfall pattern.
108
What are the 4 things that global warming affects?
- sea levels
- distribution of wild animals + plant species
- migration patterns
- biodiversity
109
How has global warming affected sea levels?
- Higher temperatures cause seawater to expand and ice to melt, causing sea levels to rise.
- It has risen a bit over the last 100 years.
110
What does an increase in sea levels result in?
- This is beginning to increase the frequency of flooding in some areas.
-If sea levels keep rising, it'll be bad news for people and animals living in low lying places and could result in the loss of habitats
111
How has global warming affected the distribution of wild animals and plant species?
- The distribution of wild animals and plant species is changing as temperatures increases and the amount of rainfall changes in different areas.
- Some species are becoming widely distributed e.g species that need warmer temperatures are spreading further as the conditions they thrive in exist over a wider areas.
112
What has happened to the distribution of species that need warmer temperatures and why?
species that need warmer temperatures are spreading further as the conditions they thrive in exist over a wider areas.
113
What has happened to the distribution of species that need cooler temperatures and why?
They are becoming less widely distributed e.g species that need cooler temperatures have smaller ranges as the conditions they thrive in exist over a smaller area.
114
How has global warming affected migration patterns?
- There have been migration patterns e.g. some birds may be migrating further north as more northern areas are getting warmer.
115
How has global warming affected biodiversity?
Biodiversity could be reduced if some species are unable to species a change in the climate, so become extinct.
116
Why do humans use lots of land for?
buildings, quarrying, farming, and dumping waste.
117
What is the effect of humans using lots of land?
- it means that less land is available for other organisms.
- sometimes the way we use land has a bad effect on the environment- for example if it requires deforestation or the destruction of habitats like peat bogs and other areas of peat.
118
What is deforestation?
Deforestation is the cutting down of forests. This causes big problems when it is done on a large scale such as cutting down rainforests in tropical areas.
119
Why is deforestation done?
- To clear land for farming (provide land for cattle and rice fields- spec) to provide more food.
- To grow crops from which biofuel based on ethanol can be produced.
120
What are the 3 issues caused by deforestation?
- less carbon dioxide taken in
- more carbon dioxide in the atmosphere
- less biodiversity
121
What does less carbon dioxide taken in mean?
- Cutting down loads of trees means that the amount of carbon dioxide removed from the atmosphere during photosynthesis is reduced.
- Tress 'lock up' some of the carbon they absorb during photosynthesis in their wood, which can remove it from the atmosphere for hundreds of years. Removing trees means that less is locked up.
122
What does more carbon dioxide in the atmosphere mean?
- Carbon dioxide is released when trees are burnt to clear land. (carbon in wood does not contribute to atmospheric pollution until it is released by burning)
- Microorganisms feeding on bits of dead food release CO2 as a waste product of respiration.
123
What does less biodiversity as a result of deforestation mean?
Habitats like forests can contain a huge number of different species of plants and animals so when they are destroyed there is a danger of many species becoming extinct- biodiversity is reduced.
124
What are bogs?
Bogs are areas of land that are acidic are waterlogged.
125
What happens to plants that live in bogs?
- Plants that live in bogs don't fully decay when they die, because there is not enough oxygen.
- The partly rotted plants gradually build up to form peat.
- So the carbon in the plants is stored in the peat instead of being released into the atmosphere.
126
However, what often happens to peat bogs?
Peat bogs are often drained so that area can be used as farmland or the peat is cut up and dried to use as fuel. It's also sold to garners as compost.
127
What is the issue with how much peat is being used?
Peat is being used faster than it forms.
128
How does destroying peat bogs add more CO2 to the atmosphere?
- When peat is drained, it comes into more contact with air and some microorganisms start yo decompose it. When these microorganisms respire, they use oxygen and release carbon dioxide, contributing to global warming.
- Carbon dioxide is also released when peat is burned as a fuel.
129
What happens to habitats when bogs are destroyed?
Destroying the bogs also destroys (or reduces the area of) the habitats of some of the animals, plants and microorganisms that live there, so reduces biodiversity.
130
What has been done to protect ecosystems and biodiversity?
Scientists and concerned citizens have put in place programmes to reduce the negative effects of humans on ecosystems and biodiversity
131
Give the 5 examples that have been put in place to protect ecosystems and biodiversity.
- breeding programmes for endangered species
- protection and regeneration of rare habitats
- reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
- reduction of deforestation and carbon dioxide emissions by some governments
- recycling resources rather than dumping waste in landfill.
132
How does breeding programmes help to protect biodiversity?
Breeding programmes have been set up to help prevent engirded species from becoming extinct.
These are where animals are bred in captivity to make sure the species survives if it dies out in the wild. Individuals can sometimes can be released into the wild to boost or re-establish a population.
133
How does protection and regeneration of rare habitats help to protect biodiversity?
Programmes to protect and regenerate rare habitats like mangroves, heathland and coral reefs have been started. Protecting these habitats helps to protect the species that live there- preserving the ecosystem and biodiversity in the area.
134
How does the reintroduction of hedgerows and field margins around fields on farms where only a single type of crop is grown help to protect biodiversity?
Field margins are areas around the edges of fields where wild flowers and grasses are left to grow. Hedgerows and field margins provide a habitat for a wider variety of organisms that could survive in a single crop habitat.
135
How does reduction of deforestation and carbon dioxide emissions by some governments help to protect ecosystems + biodiversity?
Some governments have introduced regulations and programmes to reduce the level of deforestation taking place and the amount of CO2 being released into the atmosphere by businesses. This could reduce the increase of global warming.
136
How does recycling resources rather than dumping waste in landfill help to protect ecosystems + biodiversity?
People are encouraged to recycle to reduce the amount of waste that gets dumped in landfill sites. This could reduce the amount of land taken over for landfill, leaving ecosystem in place.
137
What are some conflicting pressures for how biodiversity is maintained?
- costs money
- cost to local people's livelihood
- conflict between protecting biodiversity and protecting food security.
- development affects the environment
138
How does the factors of cost of money act as a conflicting pressure for maintaining biodiversity?
- For example, governments sometimes pay farmers a subsidy to reintroduce hedgerows and field margins to their land.
- It can also cost money to keep a watch on whether the programmes and regulations designed to maintain biodiversity are being followed.
- There can be conflict between protecting biodiversity and saving money: money may be prioritised for other things
139
How does the factors of cost of livelihood act as a conflicting pressure for maintaining biodiversity?
- reducing the amount of deforestation is great for biodiversity, but the people who were previously employed in the tree felling industry could be lefty unemployed.
- this could affect the local economy if people move away with their family to find work.
140
How does the factor of conflict between protecting biodiversity and protecting food security act as a conflicted pressure for maintaining biodiversity?
- sometimes certain organisms are seen as pests by farmers (e.g. locusts and foxes) and are killed to protect crops and livestock so that more food can be produced.
As a result, however, the food chain and biodiversity can be affected.
141
How does the factor of development affects the environment act as a conflicting pressure for maintaining biodiversity?
Development is important, but it can affect the environment. Many people want to protect biodiversity in the face of development, but sometimes land is in such high demand that previously untouched land with high biodiversity has to be used for development, e.g. for housing developments on the edge of towns or for new agricultural land in developing countries.
