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
Disadvantages of selective Breeding
- takes a long time
- offspring may not have the desired traits
How do farmers feed fish to promote fast growth
High lipid and protein foods
Regular feeding with small amount
What is Inter specific competition
Different species compete for food
What is intraspecific
Different sized fish will compete for food
How do farmers deal with Inter specific and intraspecifc competition
Place different species / sized fish in different ponds
How do farmers deal with infectious disease in fish farming
Remove dead or infected fish quickly and remove faeces asaell
Definition of biodiversity
The measure of how many different species live in an ecosystem
how does deforestation affect the carbon cycle and global warming
- plants are carbon sinks and take in carbon dioxide through photosynthesis
- when trees are cut down the carbon store is released into the atmosphere and the tree is unable to take in CO2 through photosynthesis
- trees may also be burned down which also release CO2 from combustion
What are the consequences of carbon minoxide
binds irreversibly with haemoglobin and stops oxygen binding
why is sulphur dioxide bad for the environment
sulphur dioxide reacts with atmospheric water vapour to form acid rain
can kill ecosytems and destroy organisms in rivers and lakes
how does sewage affect organisms in water bodies
- sewage provides a good source of food for bacteria
- bacteria therfore multiply rapidly
- large population of bacteria respire aerobically using up the oxygen in the water
- decreases the level of oxygen in the water resulting in the death of other organisms as they start respiring anaerobically
