Ecology Flashcards
1
Q
Define Habitat.
A
The place where an organism lives.
2
Q
Define population.
A
All the organisms of one species living in a habitat.
3
Q
Define community.
A
The populations of different species living in an environment.
4
Q
Define Abiotic factors.
A
Non-living factors of the environment. Eg:temperature
5
Q
Define biotic factors.
A
Living factors of the environment Eg: food
6
Q
Define ecosystem.
A
The interaction of a community of living organisms biotic with the abiotic parts of their environment.
7
Q
What do organisms need to survive and reproduce?
A
Things from their environment and from other organisms.
8
Q
What do plants need?
A
Light and space as well as water and mineral ions from the soil.
9
Q
What do animals need?
A
Territory (space), food water and mates.
10
Q
What do organisms do with other and their own species?
A
They compete for the same resources.
11
Q
Define the term interdependence.
A
In a community, each species depends on other species for things such as food, shelter, pollination, and seed dispersal.
12
Q
What does interdependence of all living things in an ecosystem mean if there is a major change? -such as one species being removed.
A
It can have far reaching effects.
13
Q
Define the term food web.
A
A diagram which shows what eats what.
14
Q
Define the term stable community.
A
All the species and environmental factors are in balance so that the population sizes are roughly constant. They include tropical rainforests and ancient oak woodlands.
15
Q
Give seven examples of abiotic factors.
A
Moisture levels Light intensity Temperature Carbon dioxide level for plants Wind intensity and direction Oxygen level for aqautic animals. Soil pH and mineral content.
16
Q
What does a decrease in light intensity, temperature or level of carbon dioxide level lead to?
A
Decrease in the rate of rate of photosynthesis in a plant species. This could affect plant growth and casue a decrease in the population size.
17
Q
What does a decrese in mineral content of soil eg:lack of nitrates cause?
A
Nutrient deficiencies, affects plant growth and cause a decrease population size.
18
Q
Give 4 biotic factors.
A
New predators arriving Competition (one species may outcompete another so that numbers are too low to breed) New pathogens Availability of food.
19
Q
What could a change in the environment be caused by? (ABIOTIC)
A
Increase or decrease in an abiotic factor eg:increase in temperature These changes affect the size of populations in a community, this affects population size of organisms that depend on them.
20
Q
What could a change in the the environment be caused by? (BIOTIC)
A
A new biotic factor eg: a new predator or pathogen Changes can also affect size of populations in a community which can have these knock on effects due to interdependence.
21
Q
What could a new predator do?
A
Cause a decrease in the prey population.
22
Q
Give an example of what a new predator has done.
A
Red and grey squirrels live in the same habitat and eat the same food. Grey squirrels outcompete the red squirrels so the popuation of red squirrels decreases.
23
Q
Define the term adaptations.
A
Features or characteristics that allow organisms incuding microorganisms to live in different environmental conditions.
24
Q
What does it mean by structural adaptations.
A
Features of an organisms body structure such as shape or colour.
25
How have artic animals like the Artic fox adapted?
They have white fur, so theyr'e camaflauged against the snow. Helps them avoid predators and sneak up on prey.
26
How have animals like whales that live in cold places adapted?
Thick layer of blubber and a low surface area to volume ratio to help them retain heat.
27
How have animals like camels that live in hot places adapted?
They have a thin layer or fat and a large surface area to volume ratio to help them lose heat.
28
What are behavioral adaptations?
The ways that organisms behave.
29
Example of behavioral adaptations.
Many species eg:swallows migrate to warmer climates during winter to avoid the problems of living in cold conditions.
30
What are functional adaptations?
Things that go on inside a organisms body that can be related to processes like reproduction and metabolism. (all chemical reactions that happen in the body)
31
Functional adaptations of desert animals.
They conserve water by producing very little sweat and small amounts of concentrated urine.
32
Functional adaptations of brown bears.
They hibernate over winter, lower the merabolism which conserves energy so they don't have to hunt when their is lack of food.
33
Define the term extremophiles.
They're adapted to live in very extreeme conditions. For example some can live in high tempertures in super hot volcanic vents and others live in places with high salt concentration eg:very salty lakes or at high pressure in deep sea vents.
34
What is the distribution of an organism?
Where an organism is found Eg in part of a playing field
35
What effects where an organism is found?
Environmental factors It might be more common in one area than another due to differences in environmental factors between the two areas.
36
Give an example of how environmental factors affects distribution of organisms.
Playing field daises are more common in the open the under the trees as there is more light available.
37
Give two ways to study the distribution of an organism.
Measure how common an organism is in two sample areas using quadrats and compare them. Study how distribution changes across an area eg by placing quadrats along a transect
38
What do the 2 ways to study distribution of organisms give you?
Quantitative data about the distribution.
39
What is a quadrat?
Square frame enclosing a known area eg: 1m^2 To compare how common an organism is in 2 sample areas eg: sunny and shady parts of a playing field.
40
How to use a quadrat?
Place a 1m^2 quadrat on the ground at a random point within the first sample area. Divide area int a grid and use a random number generator to pick coordinates. Count all organisms within the quadrat Repeat steps 1 and 2 as many times as possible Work out mean number of organism per quadrat within first sample space. Repeat steps 1-4 in the second sample space Compare two means
41
How to find mean number of organisms per quadrat?
Total number of organisms ÷ Number of quadrats
42
How to find the abundance or population size of an area?
Work out mean number per m2 Multiply mean by total area
43
What do food chains always start with?
A producer.
44
What is a producer?
They are usually green plants or algae and make glucose by photosynthesis.
45
When a green plant produces glucose what is it used for?
To make other biological molecules in the plant.
46
What is the biological molecules in a plant called?
Biomass which is mass of a living material.
47
What is biomass?
Mass of a living material Energy stored in a plant.
48
How is energy transferred through living organisms in an ecosystem?
When organisms eat other organisms.
49
Quickly explain how a food chain works.
Producers are eaten by primary consumers, primary consumers are then eaten by secondary consumers and secondary consumers eaten by tertiary consumers.
50
Define the term consumers
Organisms that eat other organisms
51
Define primary consumer.
First so they are the the first consumers in a food chain
52
What are secondary consumers?
Second
53
What are tertiary consumers
Third
54
What are predators and prey
Consumers that hunt and kill other animals are called predators and their prey are what they eat.
55
What is the population of any species limited by?
The amount of food available.
56
Wha happens when population of predators increases?
Prey decreases If prey increases in the predators will also increase.
57
How would you describe predator prey cycles?
Out of phase with each other. As it takes a while for one population to respond to changes in the other population.
58
What does a transect do?
Lines to help find out how organisms like plants are distributed across an area eg: if an organism becomes more or less common as you move from a hedge towards the middle of a field.
59
How do transects work?
1= mark out line in the area you want to study using a tape measure.
2= then collect data alomg a 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 data by using quadrats these can be placed next to each other along the line or at intervals for example every 2m
60
How can you calculate the percentage cover and what is it?
Percentage cover = estimating percentage area of the quadrat covered by a particular type of organism eg: by counting the numebr of little squares covered by organisms.
## Footnote
= count number of squares covered by organism Q
=Then divide by 100 and times by 100
=do this to the other organism and write it as a percentage.
61
What can evironmental challenges cause?
the distribution of organisms to change.
A change in distribution means a change in where an organism lives.
62
Give three environmental changes that can affect organsims.
Change in the availability of water
A change in temperature
A change in the composition of athmospheric gases
63
What does a chang in the availability of water cause?
The distribution of some plant species and animals in the tropics changes between the wet and dry seasons
ie: the times of year where ther is more or less rainfall and so more or les rainfall available
eg: each year in Africa, large numbers of giant wildebeest migrate moving north back south as the rainfall patterns change.
64
What does a change in temperature cause?
- Distribution of bird species in Germany is changing because of rising average temperature.
- Eg: the European bee ater bird is a medditeranean species but its now present in Germany
65
What does a change in the composition of athmospheric gases cause?
- distribution of some species changes in areas where there is more pollution.
- Eg some species of lichen can't grow in areas where sulfuric dioxide is given out by certain industrial processes.
66
What are environmental changes caused by?
Seasonal factors, geographic factors or human interaction. For example the rise in average temperature is due to global warming which has been caused by human activity.
67
Describe the water cycle.
Energy from sun makes water evaporate from land and sea, turning it into water vapour. Water also evaporates from plants this is known as transpiration.
2= warm water vapour is carried upwards as warm air rises, when it gets higher up it cools and condenses to form clouds
3= water falls from clouds as precipitation ussually rain or snow or hail. Onto land where it provides fresh water for plants and animals.
4= it then drians into the sea before whole process starts again.
68
What are living things made from?
Materials they take from the world around them.
Eg; plants turn elements like carbon oxygen hydrogen nitrogen from soil and air into complex compounds (carbs proteins and fats) that make up organisms. These get passed up food chain
69
How are material returned to the environment?
In waste products or when organisms die and decay
70
Why do materials decay?
Because they are digested by microorganisms.
71
When does decay happen faster?
Warm moist aerobic conditions becasue microorganisms are more active in these conditions.
72
What does decay do?
Puts stuff that plants need to grow eg mineral ions back into the soil
73
In a stable community what constant cycle is happening?
Materials taken out of soil and used by plants are balanced by those that are put back in
74
Describe the carbon cycle.
* carbon dioxide is removed from the athmosphere by green plants and algae during photosynthesis.
* The energy that green plants and algae get from photosynthesis is transferred up the food chain
* Carbon is used to make glucose which can be turned into carbohydrates, fats and proteins that make up the bodies fo plants and algae
* When plants and algae respire some carbon is returned to the athmosphere as co2
* When plants and algae are eaten by animals some cabon becomes part of fats and proteins in their bodies.
* The carbon then moves up the food chain
* When animals respire some carbon is returned to athmosphere as co2
* When plants and algae and animals other animals called detritus feeders and microorganisms feed on their remains. When these orgainsms respire co2 is returned to the athmophere.
* Animals also produce waste that is broken down by detritus feeders and microorganisms.
* The combustion of wood and fossil fuels also releases co2 back into the air
* So carbon and energy is constanly being recyled from ait through food chains via plants alagae animals detritus feeders and microorganisms and eventually back out into the air.
75
What is compost?
decomposed organic matter that is used a natural fertiliser for crops and garden plants.
Farmers and gardeners try to provide the ideal conditions for quick decay to make compost.
76
77
What is responsible for decomposition?
Bacteria fungi and detritus feeders
78
4 conditions that affect the rate of decay
Temperature
Oxygen availability
Water availability
Number of decay organisms
79
How does temperature affect the rate of decay?
warmer temperatures make things decompose quicker,
As the increase the rate that the enzymes work at.
If it is too hot decomposition slows down or stops as enzymes are destroyed an organisms die
Really cold temperatures slow down the rate too
80
How oxygen availability affects rate of decay?
organisms need oxygen to respire which they need to do to survive.
Microorganism involved in anarobic decay don't need oxygen though.
81
How water availability affects rate of decay?
Decay take place faster in moist environments as organisms involved in decay need water to carry out biological processes.
82
How number of decay organisms affects rate of decay?
more microorganisms and detritus feeders there are the faster decompostion occurs
83
What is biogas made from
Methane which can be burned as a fuel
84
Describe the different types of microorganisms that are used to produce biogas.
Decay plant and animal waste anaerobically this type of decay produces methane gas
Sludge waste from sewage works or sugar factories is used to make biogas on a large scale.
85
Steps of how biogas is made.
* In a simple fermenter called a generator or digestor
* Biogas generators need to be kept at constant temperature to keep microorganisms respire away
* Biogas can't be stored as liquid it needs to be high pressure
* Has to be used straight away for heating cooking lighting or to power a turbine to generate electricity.
86
Name the two types of biogas generators
Batch and continuos
87
What are batch generators?
makes biogas in small batches
Manually loaded up with waste
Waste is left to digest
By products are cleared away by end of session
88
What are continuos generators?
Make biogas all the time
Waste continuosly fed in and biogas produced at a steady rate.
More suited to large scale biogas projects
89
What do both continuos and batch generators need?
- inlet for waste material to be put in
- outlet for digested material to be removed through
- outlet so that the biogas can be piped when it is needed
90
How do you investigate the effect of temperature on the rate of decay?
1= meausure out 5cm cubed of lipase solution and add it to a test tibe. Label this tube with an L for lipase.
2= Measure out 5cm cubed of milk and add it to a different test tube
3= Add 5 drops of phenothalien indiactor to the tube containing the milk
4= Measure 7cm cubed of sodium carbonate solutionand add it to the tube containing milk and phenothalien. Makes the solution in tube go alkanline so it should turn pink
5= Put both tubes in a water bath set to 30 degrees and leave them to reach the temperature of the water bath. Stick a thermomoter in the tube to chck this.
6= Once tubes had reached 30 degrees use a calibrated dropping pippete to put 1cm cubed of lipase solution into milk tube and start stopwatch straight away
7= Sir contents of tube with a glass rod, the enzyme will decompose the milk
8= As soon as solution loses pink colour stop the stopwatch and record how long it took for the colour to change in a table.
9= Repeat experiment at different range of temperaures 10, 20 40 and 50
10= make sure you do experiment 3 times at each temperature
11= calculate mean time taken for colour to change at each temperature
12= you can make a water bath below room temperature by adding ice cubes
13= use your results to calculate rate of decay using the formula 1000/time units in s-1
91
Define biodiversity
Variety of different species of organisms on Earth or within an ecosystem
92
Why is high biodiversity important?
Ecosystems are stable as different species depend on each other for things like shelter and food.
Also maintains the right physical environement for each other
93
For the human species to survive what is important?
Good level of biodiversity maintained
94
Give some human factors which reduce biodiversity
Waste production
Deforestation
Global warming
Only recently have we taking measures to stop this continuing.
95
Why is the population increasing?
Modern medicine
Farming methods
Reduced number of people dying from disease and hunger
96
What does an increasing human population lead to?
Puts pressure on the environment as we take the resources we need to survive.
97
What do the human species demand?
A higher standard of living so we use more raw materials and more energy for manufacturing processes
So we are taking more resources from the environment, they are being used quicker than they can be replaced so they will run out
98
What does pollution affect?
Water
Land
Air
99
How does pollution affect water?
Sewage and toxic chemicals from industry can pollute lakes rivers and oceans affecting plants and animals that rely on them for survival
Chemicals that are used on land like pesticides can be washed into the water
100
How pollution affects land?
We use chemicals for farming like pesticides.
We also bury nuclear waste underground and we dump a lot of household waste into landfill sites.
101
How pollution affects air?
Smoke and acidic gases released in athmosphere can pollute air eg: sulfuric acid can cause acid rain
102
What is the temperature of the Earth a balance of?
Energy it gets from the sun and the energy it radiates back out into space.
103
How does the temperature of the planet increase?
Gases in the athmosphere naturally act like an insulting layer.
They absorb most of the energy that would noramally be radiated out into space and re-radiate it in all directions including back towards earth
104
What would happen if gas did not re-radiate back into earth?
At night there would be nothing to keep the energy in
It would quickly get cold
105
What are gases in the athmosphere called?
Greenhouse gases
106
What main greenhouse gases are rising sharply?
Carbon dioxide
Methane
107
Define global warming
Earth is gradually heating because increasing levels of greenhouse gases
It is a type of climate change and causes other types of climate change eg:change in rainfall patterns
108
Give the four reasons to be worried about global warming. (ice melt)
1= high temperatures cause sea water to expand and ice melts causing sea levels to rise. Risen a little over past 100 years. If it keeps rising it is bad for low lying areas with animals and plants. Lead to flooding so loss of habitat
109
Reasons to be worried about global warming
(distribution)
2= Distribution of many wild animals and plants may change as temperature increases and the amount of rainfall changes in areas. Species may become more widley distributed eg: species that need warmer temperatures spread further as conditions they thrive in exist over a wider area.
Other species become less well widely distributed so species that need colder temperatures may have smaller ranges as the conditions they thrive in exist over a smaller area.
110
Reasons to be worried about global warming (migration)
Could be changes in migration patterns eg: some birds may migrate further north as some northern areas are warmer
111
Reasons to be worried about global warming
(biodiversity)
Biodiversity could be reduced if some species are unable to survive a change in climate so become extinct
112
What do humans use lands for and why is it bad?
Building quarrying farming and dumping waste
So less land is left for organisms
We use land that has a bad effect on environment, if it requires deforestation of habitats like peat bogs and other areas of peat
113
What is deforestation?
The cutting down of forests. Causes big problems when on a large scale such as cutting down rainforests in tropical areas.
114
Why is deforestation done?
- clear land for farming to provide more food
- grow crops from which biofuels based on ethanol can be produced
115
Give problems fo deforestation
Less carbon dioxide taken in
more co2 in the athmosphere
less biodiversity
116
Describe how less carbon dioxide taken in is a problem of deforestation
Cutting down trees means amount of co2 removed from athmosphere during photosynthesis is reduced
Trees lock up some of the carbon that they absorb during photosynthesis in their wood, whcih can remove it from the athmosphere for hundreds of years. Removing trees means less is locked up
117
How is more carbon dioxide in the athmosphere a problem created by deforestation?
- carbon dioxide released when trees are burnt to clear land
- microorganisms feeding on bit of dead wood releases carbon dioxide as a waste product of respiration
118
Describe the problem of less biodiversity which is caused by deforestation
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
119
What are bogs?
Areas of land that are acidic and waterlogged.
Plants that live in bogs don't decay when they die as there is not enough oxygen. The partly rotte plants build up to form a peat
120
How do peats retain carbon?
carbon in plants is stored in the peat instead of being released in athmosphere
121
Uses of peat bogs
They are often drained so the area can be used as farmland or peat is cut up and dried to use as fuel.
Sold to gardeners as compost but it is used faster than it is formed.
122
What happens when a peat is drained?
Comes into more contact with air and some microorganisms start to decompose it. When microorganisms respire they use oxygen and release co2 contributing to global warming.
123
Disadvantages of peat bogs.
Co2 is released when peat is burned as fuel
Destroying bogs alsp destroys habitats of some of animal and plant microorganisms that live their so reduced biodiversity
124
How have breeding programs helped protect ecosystem and maintain biodiversity
- set up to help endangered species from becoming extinct
- Animasl are bred in captivity to make sure species survives if it dies out in the wild
- individuals can be released into wild to boost or re-establish a population
125
How have regenerating rare habitats helped protect ecosystems and biodiversity?
Programmes to protect and regenerate habitats like magroves, heathland and coral reefs have been started. Protecting these habitats helps protect species that live their- preserving the ecosystems and biodiversity
126
How has reintroducing hedge rows protect ecosystems and biodiversity
Programmes to reintroduce hedgerows and field margins around a field on farms where only a single type of crop is grown. Field margins are areas of land around the edges fo field where wild flower and grass is left to grow. Hedgrows and field margins provide habitat for a wide variety of organisms that could survive in a single crop habitat.
127
What govenments do to protect ecosystems and biodiversity
Governments have to introduce regulations and programmes to reduce the level of deforestation taking place and the amount of co2 being relaeased into the athmophere by businesses. This could reduce increase of global warming.
128
How can people help protect ecosystems and biodiversity?
People encouraged to recycle to redue amount fo waste that gets dumped into landfil sites. this could reduce the amount of land taken over for landfill leaving ecosystems in place
129
Describe the conflicting pressures which affect how biodiversity is maintained.
(money)
Protecting biodiversity costs money
Governments pay farmers a subsidy to re introduce hedgerows and field margins to their lands
Costs money to keep a watch on whether programmes and regulations designed to maintain biodiversity are being followed.
Conflict between protecting biodiversity and saving money, money can be prioritised for other things.
130
Describe the conflicting pressures which affect how biodiversity is maintained.
(local livelihood)
May come at a cost to local peoples livelihood.
ex: reducing amount of deforestation is great for biodiversity, but people who previously employed in tree felling industry left unemployed.
Affects local economy if people move away with families to find work
131
Describe the conflicting pressures which affect how biodiversity is maintained.
(food security)
Conflict between protecting biodiversity and food security.
Certain organisms seen as pests to farmers, they are killed to protect crops and livelistocks so more food is produced.
As a result food chain and biodiversity can be affected
132
Describe the conflicting pressures which affect how biodiversity is maintained.
(development)
Developlment is important but can affect environment.
People want to protect biodiversity but land is in such high demand that previously untouched land with high biodiversity has to be used for development.
eg: for housing developments on edge of towns or new farms in developing countries
133
What are trophic levels?
Different stages of the food chains. They consist of one or more organisms that perform a specific role in the food chain.
134
What are trophic levels named after?
Their location in the food chain using numbers.
135
What is the first level in a trophic called?
Trophic level one.
Each level after that is numbered in order based on how far along the food chain the organisms in the trophic level are.
136
What does trophic level one contain?
Producers are at starting point of a food chain
Called producers as they make own food by photosynthesis using energy from sun
137
What does trophic level 2 have?
Primary consumers
Herbivores that eat plants and algae
138
What does trophic level three have?
Seondary consumers
They are carnivores that eat primary consumers.
Carnivores are meat eater.
139
What does trophic level four contain?
Carnivores that eat secondary consumers are called tertiary consumers
Have no predators so at top of food chain so they are always in highest trophic level known as apex predators.
140
Why are there only 4-5 trophic levels?
So much energy is lost from the food chain at each trophic level
141
Name some decomposers
Bacteria and fungi
142
What is the role of decomposers?
decompose any dead plant or animal material left in an environment
143
How do decomposers decompose?
Secrete enzymes, they break down dead stuff into small soluble food molecules
These then diffuse into microorganisms
The process also releases nutrients in environment which producers need in order to grow
144
What is there less of every time you move up the trophic level in a food chain?
Less energy and less biomass and fewer organisms every time you move up
Biomass just means mass of living material
145
What can biomass be used for?
To construct a pyramid of biomass to represent the food chain.
146
What does each bar on a pyramid of biomass show?
Relative mass of living material at a trophic level.
(how much all organisms at each level would weigh if you put them all together)
147
148
How to draw pyramids of biomass?
Use correct scale
Order of how the food chain goes
Each bad must be labelled
149
How do prducers make glucose?
Use energy transferred by light from sun to make glucose during photosynethesis. Of the energy that hits the prodcer 1% is transferred for photosynthesis
150
What is some glucose used for by plants?
Biological molecules.
They make up plants biomass.
Biomass stores energy.
151
How is biomass transferred through an ecosystem?
When organisms eat organisms.
But not much biomass gets transferred from one trophic level to another. Only 10% is.
152
Reasons why biomass is lost between trophic levels.
* -organisms dont eat every part of the organism they consume. Ex; material that makes up plant/animal is inedible like bone. So not all biomass can be passed to next stage of food chain.
* Organisms dont absorb all the food they ingest. Stuff they dont ingest is egested as faeces
* Some of biomass taken in is converted into other substances that are lost as waste. ex: organisms use glucose in respiration to give energy for movement and insulation rather than make more biomass. Produces lots of waste co2 and water as by products
* Urea is another waste substance, released in urine with water when proteins in biomass is broken down
153
How to work out how much biomass has been lost at each level?
Take away biomass at that level with biomass available at previous level.
154
How to calculate efficiency of biomass transfer
e= biomass transferred to next level/biomass available at previous level
x100
155
What is food security?
Having enough food to feed a population
156
Name the wide range of things that can threaten food security,
1= wold population increases with the birth rate of many developing countries rising quickly
2= As diets in developed countries change demand for certain foods to be imported from developing countries can increase. So already scarce food becomes even more scarce
3= farming can be affected by new pests and pathogens or changes in the environment. Can result in loss of crops and livestock and can lead to widespread famine.
4= high input costs of farming like seeds and machinery can make it too expensive for people in some countries to start or maintain food production. So people aren't able to produce food in these areas to feed people.
5= conflicts that affect availability of food and water in some parts of the world
157
What does sustainable production mean?
Making enough food without using resources faster than they can renew
158
What are happening to fish stocks?
Declining in oceans as we are fishing too much
Less fish to eat and oceans food chain affected and some fish species may go extinct ie cod at risk from disapearing in north west atlantic
159
Give two ways fish stock can be conserved?
- fishing quotas
- net size
160
How fishing quotas conserve fish?
there are limits on number of size of fish that can be caught in certain areas, prevents certain species being overfished
161
How net size conserves fish stock?
different limits of mesh size of fish net, depending on what is being fished.
To reduce number of unwanted and discarded fish - the ones accidentaly caught eg shrimp and cod.
Using bigger mesh will let unwanted ones escape.
Younger fish will slip through the net allowing them to reach breeding age.
162
What does limiting the movement of livestock do?
Keeping them in temperature controlled envrionment and reducing movement reduces transfer of energy from livestock to environment. Makes farming more efficent as animals use less energy moving around and controlling own body temperature. So more energy is available for growth so more food can be produced form same input of resources.
163
3 ways food production can be more efficient.
1= livestocks like calves and chickens can be factory farmed, involves raising them in small pens.
2= fish factory farmed in cages where movement is restricted.
3= Some animals are also fed high protein food to further increase growth.
164
Why is factory farming controversial?
Animals are kept close together disease spread eaily
Ethical objections as some people think making animals live in unatural uncomfortable conditions are cruel.
165
Define biotechnology
Where living things and biological processes are used an manipulated to produce a useful product.
166
What is mycoprotein
used to make high protein meat substitutes for vegeterians eg: Quorn
167
How is mycoprotein made?
Fungus fusarium which is grown in aerobic conditions on glucose syrup which it uses as food.
Fungal biomass is harvested and purified to make mycoprotein in aerobic conditions
168
What is genetic engineering?
Transferring a useful gene from one organism to another
169
How can bacteria be genetically engineered to make human insulin?
* A plasmid a loop of DNA is removed from a bacterium
* the insulin gene is cut out of a human chromosome using a restriction enzyme
* Restriction enzymes recognise specific. sequences of DNA and cut the DNA at these points.
* The cut leaves one of DNA strands with unpaired bases this is called a sticky end
* Plasmid is cut open using same restriction enzyme leaving same sticky ends
* Plasmid and human insulin gene mixed together
* Lipase is added
* Joins sticky ends together to produce recombinant DNA which is two different bits of DNA stuck together
* Recombinant DNA is inserted into bacterium
* Modifided bacterium is grown in a vat under controlled conditions.
* Millions of bacteria that produce insulin.
* Insulin can be harvested and purified to treat people with diabetes
170
How can biotechnology help those in developing countries who don't have enough food to eat
1= gm crops can be grown reisitant to pests improving crop yields
2= genetically modified to grow better in drought conditions again improving crop yields
3= some crops can be modified to provide more nutritional value eg:golden rice has been genetically engineered to produce chemical thats converted in the body to vitamin A
171
Why does everybody not agree with biotechnology?
1= people go hungry as they can't afford to buy food not because their is not enough, so tackle poverty first
2= fear that countries may become dependent on companies who sell GM seeds
3= poor soil is the main reason why crops fail, so GM crops won't survive
