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
