topic 7 - ecology Flashcards
1
Q
define each of these terms :
habitat
population
community
abiotic factor
biotic factor
ecosystem
A
habitat- the place where an organism lives
population- all the organisms of one species living in a habitat
community - the populations of different species living in a habitat
abiotic factor- non- living factors of the environment
biotic factors - living factors of the environment
ecosystem- the interaction of a community of living organisms with the non living parts of their environment
2
Q
what do plants and animals need to survive and reproduce ?
A
plants need light , space, water and mineral ions
animals need space, food , water and mates
3
Q
what is interdependance?
A
when organisms rely on eachother for things such as food, shelter, pollination and seed dispersal
4
Q
give some examples of abiotic factors
A
moisture level
light intensity
temperature
carbon dioxide level
wind intensity and direction
oxygen level
soil ph and mineral content
5
Q
give examples of biotic factors
A
new predators
competition
new pathogens
availability of food
6
Q
what is an adaptation
A
a featur or characteristic of an organism that allows them to live in certain conditions
7
Q
what is the difference between structural behavioural and functional adaptations and give examples of each
A
structural = physical features, features of an organsims body structure e.g. arctic fox have white fur to camouflage in the snow
behavioural = ways that organisms behave e.g. many species migrate to warmer climates during the winter
functional = things that go on inside the organisms body that can be related to processes like reproduction and metabolism. e.g. desert anumals conserve water by producing very little amount of concentrated urine.
8
Q
what is an extremophile and what conditions could they live in
A
organism that is adapted to live in very extreme conditions e.g. some live in high temperatures, high salt concentration , high pressure
9
Q
what do food chains always start with
A
a producer
10
Q
what is a producer and give and example
A
producers make their own food using energy from the sun
usually green plants or algae
11
Q
what is biomass
A
biomass isa measure of the total mass of living material in each trophic level.
12
Q
how is energy transfered throu an ecosystem
A
when organisms eat other organisms
13
Q
what are producers eaten by
A
primary consumers
14
Q
what are the primary consumers eaten by
A
secondary consumers
15
Q
what are the two ways you can study the distribution of an organism
A
measure how common an organismis in sample areas and compare them using a quadrat
study how the istribution changes across an area using a transect
16
Q
describe the practical using a quadrat to study the distribution of small organisms
A
- divide the area you are working in into a grid and use a generator to generate random coordinates to place the quadrat.
- count the organisms within the quadrat
- repeat as muchas you can
- work out the mean number of organisms per quadrat within the first sample area.
mean = total number of organisms/ number of quadrats
- repeat 1-4 in the second sample area
- compare the two means
17
Q
describe how you would use transects to study the distribution of organisms along a line
A
- mark out a line in the area you want to study using a tape measure
- then collect data along the line
- you can do this by just counting all the organisms you are interested in that touch the line .
- or collect data using quadrats . these can be placed next to eachother along the line or at intervals.
18
Q
how would you estimate the number of organisms in a quadrat if they are difficult to count
A
calcu;ate the percentage cover by counting the number of squares covered by the organisms
19
Q
what are some environmental changes that can affect the distribution of organisms .
A
a change in the availability of water
a change in the temperature
a change in the composition of atmospheric gases
20
Q
what factors cause environmental changes
A
seasonal factors
geographic factors
human interaction
21
Q
describe the water cycle
A
- energy from the sun makes water evaporate from the land and sea , turning it into water vapour. water also evaporates from plants (transpiration )
- the warm water vapour is carried upwards (as warm air rises) . when it gets higher up it cools and condenses to form clouds.
- 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.
- it then drains into the sea before the whole process starts again .
22
Q
what causes materials to decay
A
they are broken down by micro organisms
23
Q
what increases the rate of decay
A
higher temperature
moist conditions
oxygen rich conditions
microorganisms are more active in these conditions
24
Q
describe the carbon cycle
A
- carbon dioxide 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 plants and algae.
- when the plants and algae respire , some carbon is returned to atmophere ass co2 .
- 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 .
- when the animals respire, some carbon is returned to the atmosphere as co2
- when plants,algae and animals die, other animals (detritus feeders) and microorganisms feed on their remains. when these organisms respire, co2 is returned to the atmosphere.
- animals also produce waste that is broken down by detritus feeders and microorganisms.
- the combustion of wood and fossil fuels also release co2 back into the air.
- so the carbon is constantly being cycled- from the air, through the food chains , and back out into the air.
25
what is compost
decomposed organic matter that is used as natural fertiliser for crops and garden plants
26
what factors affect the rate of decay and how
temperature - warmer temperatures make things decompose quicker because they increase the rate that the enzymes involved in decomposition work at . if its too hot ,enzymes becoe denatured
oxygen availability - many organisms need oxygen to respire which they need to do to survive
water availability - decay takes place faster in moist environments because organisms involved in decay require water to carry out biological processes.
number of decay organisms- the more microorganisms and detritus feeders there are, the faster decomposition happens.
27
what is biogas and how is it made .
what is used to mak e it on a large scale
made by anaerobic decay of waste material .
biogas is mainly made up of methane which can be burned as a fuel
lots of different microorganisms are used to produce it, they decay plant and animal wast anaerobiclaly . this produces methane gas
made in a simple fermenter called a digester or generator.
need to be kept at constant temperatures to keep microorganisms respiring away.
cant be stored as liquid so it has to be used straight away
sludge waste is used to make it on large scale e.g. sewage works
28
what can biogas be used for
heating , cooking, lighting , power turbines, generate electricity
29
what are rthe 2 main types of generator
batch generators- used to make biogas in small batches.
manually loaded with waste which is left to digest. and the by products are cleared away at the end of each session
continuous generators- make biogas all the time
waste is continually fed in and biogas is produced at a steady rate. more suited to large scale biogas projects
30
what are the 3 things that biogas generators need to have
1. an inlet for waste material to be put in .
2. an outlet fort eh digested material to be removed through
3. an outlet so that the biogas can be piped to where it is needed
31
describe a practical for investigating the effect of temperatire on the rate of decay
1. measure out 5cm cubed of lipase solution and add it to a test tube . label with l for lipase
2. measure out 5 cm cubed of milk and add it to a different test tube
3. add 5 drops of phenolphthalein indicator to the test tube containing milk .
4. measure 7cm cubed of sodium carbonate solution and addit to the test tune containing milk and phenolphthalein. this makes the solution in the tube alkaline so it should turn pink
5. put both tubes into a water bath set to 30 degreees and leave them to reach teh temperature of the water bath.
6. use a calibrated dropping pippete to put 1 cm cubes of lipase solution into the milk tube and start a stopwatch straight away.
7. stir the contents of the tube with a glas ron . the enzyme will start to decompose the milk
8. as soon as the solution looses its pink colour, stop the stopwatch and record how long the colour change.
9. repeat at a range of different temperatures.
three times at each temperature and calculate a mean
10. use results to calculate rate of decay using rate = 1000/time
32
what is biodiversity
the variety of different species of organisms on earth or withing an ecosystem
33
why is high biodiversity important
makes sure that ecosystems are stable
help maintain the right physical environment for eachotehr
34
why is the human population rising very quickly
modern medicine and farming methods which have reduced the number of people dying from disiease and hunger .
35
how does the increasing human population increase the effect on the environment
our increasing population puts pressure on the environment as we take the resources we need to survive .
people are demanding a higher standard of living so we use more raw materials but we also use mroe energy for the manufacturing processes. this means we are taking more resources from the environment quicker.
many raw materials will be used up one day
36
how can water be polluted
sewage and toxic chemicals from industry can pollute lakes , rivers and oceans, affecting the plants and animals that rely on them for survival. and the chemicals used on land( herbicides, pesticides ,fertiisers) can be washed into water .
37
how can land be polluted
we used toxic chemicals for farming . we also bury nuclear wasrter underground and dump household waster in landfills
38
how can the air be polluted
smoke and acidic gases released into the atmosphere can pollute the air ( sulfur dioxide can cause acid rain)
39
what are 4 consequences of global warming
1. higher temperatures cause seawater to expand and ice to melt, causing the sea level to rise . it hs risen a little bit over the last 100 years if it keeps rising it'll be bad news for people and animals living in low-lying places. it will lead to flooding,resultinf in the loss of habitats .
2. the distribution of many wild animal and plant species may change as temperatures increase and the amount of rainfall changes in different areas. some species may become more widely distributed or less widely distributed.
3. there could be changes in migration patterns.
4. biodiversity could be reduced if some species are unable to survive a change in the climate , so become extinct .
40
what are different things we use land for ?
building,quarrying , farming, dumping waste
41
what are reasons for deforestation
to clear land for farming to provide food .
to grow crops from which biofuels based on ethanol can be produced .
42
what are the problems with deforestation
cutting down trees means that the amount of c02 removed frm the atmosphere during photosynthesis is reduced.
trees lock up some of the carbon that they absorb during photosynthesis in their wood which can remove it from the atmosphere for hundreds of years
carbon dioxide is releasedwhen trees are burnt to clear land
microorganisms feeding on bits of dead wood release carbon dioxide as a waste product of respiration
habitats like forests can contain a huge number of species so when they are destroyed there is a danger of many becoming exticnct. biodiversity is reduced
43
what are peat bogs and how do they add more c02 to the atmosphere
bogs are areas of land that are acidic and waterlogged.
plants that live there dont fully decay when they die because there isnt enough oxygen .
the partly rotted plants build up to form peat.
so the carbon in the plants is stored in the peat instead of being released in the atmosphere.
they are often drained so the area can be used as farmland or it is cut up and burnt as fuel. also sold as compost.
when peat is drained it comes into contact with air and so organisms start to decompose it and release carbon dioxide.
carbon dioxide is also released when peat is burned as fuel .
destroying bogs also destroys the habitats of some of the animals, plants and microorganisms that lives there so reduces biodiversity
peat bogs are nonrenewable
44
what are some programs that have been set up to protect ecosystems and biodiversity
breeding programmes have been set up to help prevent endangered 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 be released into the wild to boost or re establish a population .
programmes to protect and regenerate rare habitats like mangroves,heathland and coral reefs have been started. protecting these habitats help to preserve the ecosystem and biodiversity in the area.
programmes to introduce hedgerows and field margins around fileds on farms where a single type of crop is grown .field margins are areas of land around the edges of a field where wild plants are left to grow. hedgerows and field margins provide a habitat for a wider variety of organisms that could suurvive in a single crop habitat.
regulations and programmes to reduce deforestation and amount of co2 released by businesses .
people are encouraged to recyle to reduce waste in landfills.
45
what conflicting pressures affect how biodiversity is maintained
1. it costs money , e.g. governments pay farmers to reintroduce hedgerows and field margins.
can also cost money to keep a watch on whether the programmes designed to maintain biodiversity are being followed.
2. protecting biodiversity may come at a cost to peoples livelihoof. e.g. reducing deforestation can reduce jobs in that field.
can affect local economy if people move to find work .
3. conflict between protecting biodiversity and protecting food security.
sometimes certain organisms are seen as pests by farmers and are killed to protect crop or livestock so that more food is produced.
4. development can affect the environment. sometimes land is in such high demand that previously untouched land with high biodiversity has to be used for development e.g. house development or new agricultural land in developing countries.
46
what is a trophic level
trophic levels are the different stages on a food chain
47
what does trophic level one contain
producers
organisms at the start of the food chain that make their own food from energy from the sun
48
what is in trophic level 2
primary consumers .
herbivores that eat the plants and algae (producers)
49
what is in trophic level 3
secondary consumers
carnivores
50
what is in trophic level 4
tertiary consumers
carnivores that eat carnivores
carnivores at the top of the food chain are apex predators
51
explain how decomposers break down dead material in an environment
they do this by secreting enzymes that breal the dead stuff into small soluble food molecules which then diffuse into the microorganisms
52
what does each bar on a pyramid of biomass show you
relative mass of living material at a trophic level
53
describe how a pyramid of biomass is structured
bottom bar is trophic level one.
always represents the producer
each bar up is a trophic level up .
there is less energy and biomass everytime you move up a stage.
54
how much as a percentage of biomass is transferred to the next trophic level
around 10 percent
55
why is biomass lost between trophic levels
organisms dont always eat every single part of the organism they are consuming.
organisms dont absorb all of the stuff in the food the ingest
some of the biomass taken in is converted to other substances that are lost as waste .e.g. organisms use a lot of glucose in respiration to provide energy for movement and to keep warm .this produces waste carbon dioxide and water.
urea is another aster released in urine .
56
what is the equaiton to calculate the efficienct of biomass transfer
efficiency = biomass transferred to next level / biomass available at the previous level X 100
57
what are things that can threaten food security
1. the increasing world population and devloping birth rate.
2. as diets in developing countries change, the demand for certain food to be imported from developing countries can increase. this means alwready scarce food sources can become more scarce .
3. farming can be affected by new pests and pathogens or changes in the environ,ent ocnditions. this can result in the loss of crops and livestock. and can lead to widespread famine.
4. the high input costs of farming can make it too expensve for people in some countries to start or maintain food production , meaning that there sometimes arent enough people producing food in these areas to feed the people.
5. in some parts of the world , there are conflicts affecting the availability of food and water.
58
how can fish stocks be maintained ?
fishing quotas - limits on number and size of fish that can be cuaght in certain areas. this prevents species form becoming over fished .
net size - limits of mesh size of the fish net depending on whats being fished. this is to reduce the number of unwanted and discarded fish - ones that are accidentaly caugth. using bigger mesh size will also let the younger fish slip through the net allowing them to reach breeding age.
59
what reduces the energy transfer of energy form livestock to the environment.
limiting movement
keeping them in temperature control environments
60
explain how food production from livestock farming can be made more efficient
livestock like calves and chicken can be factory farmed , this involves raising them in small pens.
fish can also be factory farmed in cages where their movement is restricted .
some animals are fed high protein food to further increase their growth .
61
why are factory farming methods controversial
animals kept so close together , disease can spread easily.
people belive that they are living in unnatural and unconfortable conditions which is cruel
62
how is mycoprotein produced
using biotechnology, large amounts of microorganisms can be cultured industrially under controlled conditions in large vats for use as a food source.
mycoprotein is used to make high protein meat substitutes for vegetarian meals.
it is made from the fungus fusarium which is grown in aerobic conditions on glucose syrup which it used as food.
the fungal biomass is harvested and urified to produce mycoprotein .
63
how can a bacteria be genetically engineered / modified to make human insulin
a plasmid 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 the dna strands with unpaired bases - this is called a sticky end.
the plasmid is cut open using the same restriction enzyme - leaving the same sticky ends
the plasmid and the human insulin gene are mixed together.
ligase is added. this joins the sticky ends together to produce recombinant dna.
the recombinant dna isinserted into a bacterium.
the modified bacterium is grown in a vat under controlled conditions.
you end up with millions of bacteria that produce iinsulon.
the insulin is harvested and purified to treat people with diabetes.
64
how can crops be genetically modified.
GM crops can be produce that are resistant to pests. improving crop yields
they can be genetically modified to grow better in drought conditions.
some crops can be modified to provide more nutritional value. e.g. golden rice has been genetically modified to procude a chemical that is converted in the body to vitamin a .
65
why do some people dissagree with GM crops
many argue that people go hungry because they cant afford food not becasue there isnt any . so they argue you need to tackle poverty first.
there are fears that countries may become dependant on companies who sell GM seeds.
sometimes poor soil is the main reason why crops fail, and even GM crops wont survive.
