CHAPTER 18 Flashcards
WHAT IS BIODIVERSITY
the variety of different species of orangisms on earth or in an ecosystem
why is a high biodiversity important
it makes sure the ecosystem is stable because different species depend on each other for things like food or shelter the loss of one species has little impact
2 human activities impacting biodiversity
deforestation
global warming
what has the population of humans increased so much 2
development in medicine - stops people dying
development in farming - stops people starving q
why does a higher number of humans have a larger impact on the environment
we are demanding a higher standard of living
so we use more raw materials and more energy
raw materials are being used quicker than they are being replaced
4 main uses of land
building infrastructure
farming
mining
landfill
how is the growing population impacting land use
the growing population need more land for house etc so we destroy habitats affecting biodiversity
how is waste impacting the air around us
smoke and acidic gases can pollute the air eg acid rain
how is waste impacting the land around us 3
we use toxic chemicals for farming
we bury waste in landfill
nuclear waste is left underground
how is waste impacting the water around us
sewage and toxic chemicals from industry pollutes lakes and rivers
how do people pollute the land in developed countries 2
household waste
industrial waste
how does farming pollute the water
weadkillers and presiticides are used which try to keep these crops healthy
these run off into rivers and stream
they become part of food chains as animals ingest infected water
bioaccumulation- each stage along the food chain more and more toxins build up the the animals
how are we affecting plant life in the water
fertilisers and untreated sewage flow into rivers and streams
this leads to a build up of nitrogen
this stimulates algae and weeds to grow quickly
plants die because they are outcompeted
how are we affecting animal life in water
fertilisers and untreated sewage flow into rivers and stress leading to a build up of nitrogen
this stimulates algae and weeds to grow quickly
plants die because they are outcompeted
this leads to more decomposers
decomposers use up dissolved air in the water
the animals in the water now dont have enough oxygen and can die too
2 ways in which the pH oh water is tested
instruments used to show proportion of toxic chemicals bioindicators
how is acid rain formed
fossil fuels burned
they contain sulphur impurities
the sulfure reacts with oxygen when it burns to form suffer dioxide
acidic sulfur dioxide and nitrogen dissolve in rainwater rto form sulphuric acid snd nitric acid
effects of acid rain 3
kills plantlike
if it soaks into the soil, it can destroy the roots of plants
can infect water ways making them uninhabitable
why is acid snow worse than acid rain
it will all melt in one go
why will clean countries still be affected by acid rain
the sulfur dioxide and nitrous oxides are carried high in the air by winds infecting other countries
ways in which have attempted to reduce the effect of acid rain
low sulfur diesel and pretors
strict emission levels
catalytic converters remove polluting gases
what has happened to the amount of acid rain over the past 40 years
it has decreased
impact of smoke on human health
particles breathed in and can damage cardiovasuaclar system
how is smoke damaging our world
the particles in smoke gather in the atmosphere
they reflect sunlight so less light reaches earth
what is smog
a combination of chemicals and smoke that can be seen in the air
impact of suffuse dioxide on people
breathing difficulties
4 impacts of global warming
thermal expansion
changes in distribution of wildlife
changes in migration patterns r
reduced biodiversity
problem of rising sea levels
extreme flooding and loss of habitat
process of global warming
gases in the atmosphere act like an insulating layer
they can absorbs the energy that would be reradiated out to space and reflect it back towards earth
what are the two main greenhouse gases
carbon dioxide and methane
3 main reasons for deforestation
farming
rear cattle
to grow crops to be used as biofuels
what are the three ways in which deforestation increase co2 levels in the atmosphere
less co2 taken in by the trees through photosynthesis
combustion = more co2
decomposers release co2 through respiration
why does deforestation reduce biodiversity
habitats like forests contain a large number os species so when their habitats are destroyed there is an increased risk of them becoming extinct
how is peat made
when plants the live in bogs die they dont fully decay because it is too acidic and there isn’t enough oxygen over time this builds up to form peat
what are bogs
areas of land that are acidic and waterlogged
why are peat bogs so important
huge store of carbon and home to many unique animals
why are peat bogs being destroyed
the peat is cut up and used as a fuel or compost and the area is needed for farmland
why is peat non renewable
it is being used faster than it is being made
why does the sourcing of peat increase co2 levels
when peat is drained it comes into contact with air and microorganisms start to decompose it . hen these organisms respire co2 is released
why are deforestation and methane levels linked
the land which has been cleared by deforestation is often used for cattle farming and growing rice both of which are a source of methane
why will there be more co2 in the air as the oceans warm up
co2 is less soluble in warm water so they are less effective
carbon sinks
why will the distribution of animals change
climate change may make some conditions more favourable for animals more than others so for some their range will expand and for others it’ll shrink
how will global warming impact migration patterns
changing temperature and seasons
5 ways in which we are trying to maintain ecosystems
recycling
reduction of co2 emission and deforestation
breeding programmes for endangered species
protection of rare habitats
reintroduction of hedges
problems with breeding programmes 2
must avoid inbreeding
many animals dont reproduce easily or quickly
what are breeding programmes and will they help
animals are bred in captivity to ensure a species survives if they die out in the wild
they can then be released into the wild to boost or reestablish a population
3 examples of rare habitats that are now becoming protected
coral reefs
heathland
mangroves
what is being done to protect coral reefs
global warming is being tackled as acidic pH Is the biggest threat
what is being done to protect heathland
protecting it for developers and reestablishing its unique characteristics
eg letting horses graze
what is being done to protect mangroves
salinity of water in being monitored
why is it good that rare habitats are being protected
helps to protect the species that live there, mainting biodiversity
what are people planting hedgerows
they provide a valuable habitat for a wide range on species in the uk
how is costa rica benefiting from reduced co2 emission
sustainable tourism
what are countries doing to promote recycling 3
encourage composting
companies ar now recycling manufacturing waste
taxes pn putting material in landfill
4 argument against maintaining biodiversity
it is expensive - to set up and matinain schemes
could affect peoples livelihoods eg timber industry
development is important
we must protect our food security
what are trophic levels
the position of organisms in a food chain
what is trophic level 1
producers eg green plants and algae
what is trophic level 2
primary consumers eg herbivores
what is trophic level 3
secondary consumers eg carnviores
what is trophic level 4
tertiary consumers eg carnivores that eat other carnivores
what is biomass
the mass of material in living organisms
how do decomposers work
they secrete enzymes that break own the dead bodies into food molecules
these are diffused into the decomposers
problem with measuring the dry biomass of an organism
you have to kill it and dry it out first
problem with measuring the wet biomass of an organism
the amount of water in an orgnaism varies throughout the day
what happens to the amount of energy and biomass as you move up the trophic level
it decreased
why does the amount of biomass decrease as you go through trophic levels 3
not all part of the organism are eaten some of the biomass is excreted
lots of biomass used to keep organisms alive eg respiration
what is the incident energy
sunlight
why is biomass lost in faeces
a herbivores
b carnivores
a many herbivores dont have the enzymes to break down cellulose so the food is excreted
b carnivores cant eat every bit of their prey
how much of the suns energy is used for photosynthesis
1%
why is biomass lost in waste
plants and animals need glucose to stay alive - it supplies energy for the living processes in the body
some biomass is lost as carbon dioxide heat and water the waste products of repsiration
why will a more active animal transfer less biomass
active contracting muscles carry out a lot of respiration which leads t the loss of its of heat that would’ve been transferred as biomass
why is biomass lost through temperature control
mammals use lot of biomass in respiration in order to maintain a constant temperature
how to calculate the efficiency of biomass transfer
efficiency = biomass transferred to the next level / biomass available at previous level x 100
6 factors affecting food security
increasing birth rates changing diets new pests and pathogenss cost of agricultural inputs conflicts changing environemtn
what is food security
having enough food to feed the population
why is an increasing birth rate affecting food security
there are more people to feed
how can changing diets affect food security
in developed countries people want to try exotic good which need to be imported
this deprives local people of a traditional food source or drives up the prices so they cant afford it
how can new pests and pathogens affect food security
this can result in lack of crops produced and lease to widespread famine
how do environmental changes affect food security
flooding = no crops drought = no crops
how can the changing price of agricultural inputs affect food security
in developing countries the expense of farming meat some people cant afford it so they cant grow food and starve
how can conflict affect food security
people cant access food and water and often infrastructure such as water pipes are destroyed
what is sustainable fish production
maintaining fish stocks at a level where fish can continue to breed
how can fish production be conserved 2
fishing quotas
net size
what is sustainable food production
producing food in ways that supplies the whole population for many years
3 ways of making food production sustainable
taking care of fishing in oceans so fish supplies dont run out
maintaining soil quality so plants grow well consistently
how is biotechnology helping in food production
gm crops are being developed to give better yields or more nutritional value
3 advantages of gm 3
pest resistant
more nutritional value
3 disadvantages to gm crops
poor soil cant be changed by gm crops
people cant afford the seeds
unaware of long term impact
what is mycoprotein
it is high protein meat substitute for vegetarians
process of creating mycoprotein
the fungus fusarium is grown cheap
glucose syrup
aerobic conditions were provided in fermenters
the biomass is then harvested and purified
it is a pale yellow solid that can be shape and flavoured
2 disadvantages of fishing quotas
if fishermen have caught too much they throw it back into the sea -may affect income and food security
what do farmers often do to increase the growth of livestock and why
they feed animals with animals as it is protein rich improving growth
why would it be most efficient if humans lived off plants
there would only be two phases in the chain so less energy would be lost
why does limiting the movement of livestock increase efficiency
they dont use their muscles much this reduced respiration
so less energy is lost
why does keeping animals in a temperature controlled environment controlled environment improve efficiency
they dont have to use much biomass to respire and keep warm so less biomass is lost
process of fish farming
they are caught and live in cages
they are fed high protein meals
they have restricted movement because of this they grow and mature rapidly
why are fish being specifically bred
for fast growth
disadvantages of farming animals in factories 4
disease spread quickly
ethic
they need constant monitoring
expensive q
how is the farming of cattle fish and chickens made efficient
they are farmed in factories in specially monitored conditions
why are intensive farming methods used
there has been an increase in demand for cheap meat products
how can bacteria be modified to produce human insulin
a plasmid is remove from a bacterium
the insulin gene is cut form a human chromosome using a restriction enzyme . the cut leaves on the bases unpaired which is called the sticky end
the plasmid is cut open using the same enzyme, leaving the same sticky ends
the plasmid and insulin gene are mixed
ligase an enzyme is added to join the two sticky end together to make recombinant DNA this is inserted into the bacterium
the bacterium multiplies under controlled conditions
what does a restriction enzyme do
it recognises specific sequences of dna and cuts the dna at these points
the cut leaves on the the dna stands with unpaired bases this is called sticky end
what is recombinat dna
when an enzyme joins two sticky end together
two different bits of dna stuck together
how do seasonal changes impact the distribution of organisms
in temperate parts of the world many factors such as temperature change between seaosns. some organisms will migrate to find more favourable conditions
how do geographical changes impact the distribution of organisms
many plants and animals have adaptations that enable them to survive in specific conditions so will move when the conditions arent favourable
negative impact humans have on the environment 3
GLOBAL WARMING Climate change
acid rain
pollution
positive impacts humans have on the environment 3
preserving rain forests
reducing and monitoring pH
conservation measures
what are organisms doing as a result of global warming
relocating to cooler nd higher areas
what are the three things that affect the distribution of an organism
seasonal changes
human impacts
geographical change
what has happened to dartford warbler as a reuslt of climate change
in the 1900s they lived in southern europe as temperatures increase they have moved to england and wales
what do scientists predict will happen to many bird species in europe by the end of the century
They will have moved out of europe or will become extinct
