Harnessing biology Flashcards
how does high light intensity create a higher crop yield
more photosynthesis, keeps stomata open
how does high CO2 create a higher crop yield
photosynthesis reactant
how does warm temperature create a higher crop yield
more kinetic energy for enzymes
how does water create a higher crop yield
- reactant for photosynthesis
- transports mineral ions
- transpiration
uses of MG in fertiliser
makes chlorophyll
uses of NO3 in fertiliser
proteins + DNA
uses of PHO3 in fertilisers
DNA
uses of K in fertilisers
enzyme reactions
What are the advantages of organic fertiliser
- improves soil structure
- greater range of minerals
- releases minerals over a long time
- cheaper
What are the disadvantages of organic fertiliser
- slow acting, has to be decomposed
-bulkier more difficult to apply - may contain pests
What are the advantages of inorganic fertiliser
- mineral ions are released immediately
- contents are known
- easy to apply
What are the disadvantages of inorganic fertiliser
- can lead if eutrophication as fertiliser is soluble
- requires regular reapplication
What is eutrophication
- Heavy rain leaches minerals from fields
- fertiliser is washed into nearby bodies of water
- high conc of nitrates and minerals caused an algae bloom
- algae bloom covers surface and blocks sunlight
- plants underneath cannot photosynthesise and die
- number of bacteria increase
- dead plants are decomposed by bacteria
- bacteria despiste reducing the oxygen in the water
- low oxygen causes other organisms and animals to die
What are the advantages of pesticides
- reduces pest population instantly
- can kill a whole population
What are the disadvantages of pesticides
- not specific to the pest
- pest can become resistant
- chemical can affect higher up the food chain
What are the advantages of biological controls
- only needed to be introduced once
- pest specific
- pest will not become resistant
- no effect on other animals in the food chain
What are the disadvantages of biological control
- takes time to reduce population
- not all population is killed
What does the cooling jacket do in a fermenter
Removes heat energy stopping the fermenter from over heating and the enzymes denaturing
What does an air filter do in a fermenter
Maintains sterile conditions so no other bacteria is grown
What are the purpose of stirrers in a fermenter
Keep the solution from settling and to oxygenate all the parts
Explain why temperature must be controlled in a fermenter
So the enzymes are working at their optimum temperature which allows the best growth.
What is the bacteria used to make yoghurt
Lactobacillus
Describe the stages to make yoghurt
- pasteurise the milk to remove any harmful microorganisms by heating to 95 degrees
- milk is homogenised to dispense fat globules
- cooled to 40 degrees for optimum enzyme activity for lactobacillus
- Lactobacillus respires producing lactic acid
- lactic acid has a low PH and denatures milk proteins causing the yoghurt to thicken
- yoghurt is then cooled to 5 degrees and stirred
What are the steps of selective breeding
- Humans select the best individual organisms with the best desirable traits and breed them together
- creates a range of offspring
- select the offspring with the desired trait and repeat process
- repeat for many generations
