5 use of biological resources Flashcards
how can selective breeding develop plants with desired characteristics?
- decrease resistance in food crops
- increase crop yield
- more weather tolerant
- better tasting food
how can selective breeding develop animals with desired characteristics?
- needs variation to take place
- use the offspring with the best combination of features
- produced for size
negatives of selective breeding in animals:
- reduces genetic diversity
- increased incidence of genetic conditions
- increased vulnerability to disease/ predation/ natural disaster
how can glasshouses and polythene tunnels be used increase crop yield?
- increase light
- increase CO2
- increase humidity
- control temp
- monitor pH of soil
what does increased carbon dioxide do in glasshouses?
- produced during respiration
- used during photosynthesis
- more CO2= more photosynthesis
- more photosynthesis= higher crop yield
what does increased temperature do in glasshouses?
- increases rate of respiration + photosynthesis
- increases rate of growth
- increases enzyme activity
how can the use of fertiliser increase crop yield?
- plant food which contains mineral ions for plant growth
- can be organic or inorganic
- extra mineral ions
advantages of using biological control:
- more natural
- no resistance formed
- no need to reapply- cheaper
- pest specific
disadvantages of using biological control:
- can go wrong- predators start eating crops
- takes a while to reduce population
- not all pests eaten
advantages of using pesticides:
- fast acting
- immediate effect
- targets and kills the entire population
disadvantages of using pesticides:
- need to reapply
- may kill other species
- toxic to food chain- may cause bioaccumulation
role of yeast in the production of food:
- releases carbon dioxide to make bread rise
practical: investigate the role of anaerobic respiration by yeast in different conditions:
- effect of temp
- higher temp= faster respiration
- until enzymes denatured
role of lactobacillus in yoghurt production?
- bacteria use lactose to respire anaerobically, producing lactic acid, this causes a fall in pH, which denatures proteins and causes them to coagulate
what is an industrial fermenter used for?
- to grow micro- organisms on an industrial scale
what is the purpose of a cooling jacket on an industrial fermenter?
- keeps enzymes working at optimum temperature
- reduces temperature after respiration heats up contents as respiration produces heat
why is it important to maintain aseptic conditions in an industrial fermenter?
- to prevent unwanted micro organisms
why is it important to add air and nutrients to the fermenter regularly?
- air- allows oxygen for aerobic respiration
- glucose- for respiration
- amino acids- for growth
why is it important to maintain the optimal temperature and pH for the growth of a microorganism in an industrial fermenter?
- so enzymes don’t denature
- measure by electric probe
why is it important to stir the contents of an industrial fermenter regularly?
- stops contents from settling to the bottom
- stops condition becoming anaerobic
how to promote growth of fish:
- high lipid and high protein food to promote rapid growth
- regular feeding and small amounts- ensure that most gets eaten
- selective breeding to grow desirable fish
issues with breeding different fish:
- interspecific competition
- predation
what is interspecific competition?
- differed species will compete for food and some species will be wiped out- could place species in different ponds/ tanks
what is predation?
- carnivorous species will prey on other fish- could place cover over ponds to reduce predation from birds
issues with too many fish in one pond:
- intraspecific competition
- infectious diseases
what is infraspecific competition?
- larger fish will outcompete smaller fish for food, large individuals may prey on smaller individuals
what are infectious diseases in fish farming?
parasites and pathogens
spread quickly if fish are too close together- could separate fish by age and size, remove dead or infected fish and treat the water with antibiotics to kill the bacteria
what is biodiversity
- variety of living organisms in a particular habitat
practical: investigate the distribution of organisms in their habitats and measure biodiversity using quadrats:
- quadratic practical
effects of deforestation:
- leaching
- soil erosion
- disturbance of evapotranspiration
- disturbance of carbon cycle
- disturbance of the balance of atmospheric gases
consequences of polluting water by sewage:
- provides good nutrients of bacteria
- bacteria therefore multiply rapidly
- use up oxygen as they are respiring
- increases biological oxygen demand
- this decreases the overall level of oxygen and kills fish as they cannot respire
- can also lead to eutrophication
consequences of carbon monoxide:
- binds with haemoglobin in blood- stops oxygen from binding- can’t transport oxygen so can’t respire
consequences of sulphur dioxide:
- dissolves in water to form dilute sulphuric acid and nitric acid
- this rain then has a damaging effect on trees, freshwater and soils
- effects enzymes
consequences of leaching from soil:
- causes eutrophication
- this decreases oxygen, kills fish and organisms
