B18: Biodiveristy Flashcards
biodiversity?
variety of different species of organsims on earth/within an ecosystem
how does biodiversity ensure stability of ecosystems?
reduces dependency on other organsims for shelter and food
how are human activities reducing biodiversity?
population growth means :
- more land used for houses, factroies etc
- more waste
- pollution of water -> more sewage/toxic chemicals pollute water
sources of water pollution?
toxic chemicals/pesticides- run off into water sources - lead to death/failure to breed
untreated sewage - sewage is good food for bacteria, so will increase and deplete oxygen levels in water as respire aerobically –> EUTROPHICATION /death of animals
fertilisers - increases algae/water plants so water plants at bottom die bc lack of sunlight
sources of land pollution?
toxic chemcials
discarded rubbish - toxic chemicals from rubbish/landfill can go into soil
sources of air pollution?
sulfur dioxide/nitrogen oxides - acid rain can damage leaves, flowers
- can make rivers too acidic -> death of aqautic animals
how do humans reduce amount of land available?
building, quarrying, farming, dumping waste
what are peat bogs?
bogs are areas of land that are waterlogged /acidic
- plants that die dont fully decay due to lack of oxygen
- the partly decomposed plant matter accumilates over time to form peat
why are peat bogs destroyed /impact?
- to be used for farming
- peat can be used for fuel
- produce compost to increase food production
IMPACT : CO2 released when peat is burned as fuel
why is deforestation happening in tropical areas?
- provide land for farming cattle/rice fields
- grow crops for biofuels
consequence of deforestation?
extinction/loss of biodiversity
soil erosion - tree roots stabalise soil
- without trees , minerals are unused so washed away into rivers/lakes by rain (leaching)
flooding - topsoil will be loose/unstable so washes away –> increases flooding
CO2
consequences of global warming?
Melting ice caps
Rising sea levels
increasing temps –> flooding, drought
increased migration of species
extinction –> decrease biodiversity
positive human interactions with ecosystems?
- maintaining rainforests
- reducing water pollution
- preserving areas of scientific interest
- replanting hedgrows/woodlands
negative interactions with ecosystems?
- production of greenhouse gases
- so2 from factories –> acid rain
- chemical from agriculture
- clearing land to build on
how to reduce our negative impact on ecosystems?
- breeding programs - stop endangered species from extinction
- protect rare habitats - stop extinction of animals in that area/ may have to be regenerated
- reintroduction of hedgrows/field margins around land where only 1 type of crop is grown - maintains biodiveristy (provide habitats/ field lines allow wild flwoers/grasses to grow)
- reduce deforestation/CO2 emissions- slows down global warming
- recycling - reduces land taken up by landfill
trophic levels ?
level 1 : PRODUCERS - photsynthetic organisms (plants and alage)
level 2 : PRIMARY CONSUMERS - herbivores
level 3 : SECONDARY CONSUMERS - predators
level 4: TERTIARY CONSUMERS - predators
level 5 : QUATENARY- APEX predators
how do decomposers break down organic matter?
secrete enzymes
- break food into small soluble food molecules
- these molecules then absorbed by decomposers
what is biomass pyramid ?
shows relative biomass at each trophic level
why is the biomass less as u go up pyramid?
not all food consumed is converted to biomass
- some biomass lost in respiration/ urine
how is bomass transfered?
Primary consumers eat producers , they break down biomass of producer and use the chemical energy to increase/sustain own biomass
- this repeats at every trophic level
efficiency of biomass transfer equn?
Biomass transferred to next level/biomass available in previous level x 100
factors effecting food security?
INCREASED BIRTH RATE
CHANGING DIETS
NEW PEST/PATHOGENS - destroy crops
CLIMATE CHANGE - affect food production
CONFLICTS
how can efficency of food production be increased ?
aim to increase the amount of energy converted into biomasss by restricting energy transfer from animals to environment by:
1. limiting movement - kept in cages
2. controlling temps of surrounding - livestock kept at optimum temp so use less energy regulating body temp
3. fed high protein food to increase growth
ethical objections to intensive farming methods?
- disease can spread easily
- unethical to make animals live in unnatural/uncomfortabe conditions
advanatges and disadvatages to modern farming techniques?
AD: livestock given antibiotics with food
- growing one type of crop increases yield/profit
- using fertilisers increase plant growth –> increase food yield
DIS : unethical to keep animals confined
- giving livestock antibiotics may cause antibiotic resistance
- growing 1 type of crop decrease biodiviersity
- fertilsers can cause eutrophication
how to maintain fish stocks at a level where breeding continues?
sustainable fisheries - fisheries where overall population size doesnt decrease
- bc no fish caught doesn’t exceed no. fish born
controlling net size - allow unwanted species to escape in larger net gaps
- juvenile fish can escape so can reach breeding age/produce offspring before caught
fish quotas - limit no./size of fish species that can caught in an area
how can Fusarium produce mycoprotein?
fungus is grown in aerobic conditions/provided with glucose syrup as food source
- fungus grows and multiplies in fermenter
- fungus is then hervested/purified to produce mycoprotein -> protein suitable for vegs
how is biotechnology used to provide sufficient food fro increasing population?
Mycoprotein - protein rich products good for vegetarians
GM crops - modified to be resistant to pests/weather –> incresing yield
- modifying them to increase nutritional value
Required Practical : decay
Place 20cm cubes of fresh milk in 3 beakers
- decide 3 temps you’ll investigate and write in each beaker
Use universal indicator to determine pH of each beaker
- cover each beaker in cling film/ put in water bath to get them to same temp
- universal indicator again for each of the beakers after 24,48,62 hrs
