Use of Biological Resources Flashcards
How can greenhouses and polyethene tunnels increase crop yield?
The conditions are kept at the optimum for growth, including the use of artificial lighting and trapping heat from the sun
How does increased temp increase the crop yield?
-Enzymes work more efficiently at higher temperatures and reaction rates are faster
-Enzymes are involved in key growth processes and photosynthesis
How does a continuous supply of carbon dioxide increase the crop yield?
-Co2 is needed for photosynthesis which is needed to provide energy for growth
-Without a constant supply for enough CO2, it may become a limiting factor and so the rate of photosynthesis is slower
How do fertilisers increase crop yield?
Fertilisers provide nutrients for the plant which are needed for growth to make crops large and give a plentiful yield
State 2 methods of pest control
-Biological control
-Pesticides
What is biological control?
A method of controlling plant pests by deliberately introducing organisms that feed on the pests to decrease the number of them
Give 2 advantages of pesticides
-Cheap
-Easy to use
3 disadvantages of pesticides
-They are not specific so it can kill other insects that are not pests
-They can contaminate water sources
-They have to be applied more than once.
Give 3 uses of yeast
-Fermentation of alcohol
-Baking
-Making biofuels
How does yeast cause bread to rise?
The yeast breaks down the sugars in the bread in respiration and produces carbon dioxide which causes the bread to rise
Describe how yoghurt is made from milk
-Lactobacillus is used to break the lactose in milk into lactic acid
-Lactic acid lowers the pH of the milk which causes proteins to denature and makes milk into yoghurt.
What is fermenter used for?
To produce large cultures of microorganisms
State 5 things that need to be controlled in an industrial fermenter
-Temperature
-pH
-Nutrient levels
-Oxygen levels
-Contamination
Write in order the parts of a fermenter
-Gases out
-Nutrients in
-Mixing blades
-Water jacket for temperature control
-Products out
Give 6 methods used in fish farming to increase yield
-Ensuring good water quality
-Controlling predation
-Controlling disease
-Clearing wast
-Managing feeding
-Selective breeding
How is water quality mantained in fishing areas?
-Waste removed
-Pathogens killed
What is the difference between intraspecific and interspecific predation, in terms of fish?
Interspecific predation-Where other species eat the fish
Intraspecific predation→Where fish eat one another
Describe how selective breeding is carried out
-Organisms with the desired traits are selected
-These organisms are bred together
-This process is repeated until the offspring have the desired characteristics
What genetic engineering?
Altering the genome of an organism
How are new genes introduced into an organism
-The organism’s genes are cut using restriction enzymes to create sticky ends
-The DNA from a bacterium is also cut to produce sticky ends
-The gene is inserted into the bacterium and joined together by DNA ligase enzymes
3 benefits of genetically modified crops
-The plants are resistant to herbicides and disease
-Grow bigger and quicker
-They can grow in harsher environments and without the need to continue to top up nutrients frequently
What is a transgenic organism?
An organism that contains foreign DNA
Describe the process of tissue culture
-Small cuttings (explants) are taken from the plant that you wish to clone
-The cuttings are placed in an agar dish containing growth hormones
-Once the new plants have grown enough, they are transferred to soil
2 benefits of tissue culture (micropropagation)
-Can produce many plants quickly
-Can produce lots of plants with desirable traits
Describe how animal cell cloning can be carried out
-The nucleus is removed from an unfertilised egg cell to create an enucleated cell
-The nucleus is removed from a cell from the animal you wish to clone
-The nucleus is placed in the enucleated cell and cell division is triggered by an electric shock
-Once the embryo gets big enough, it is placed in a surrogate mother
Give one example of a human protein made by a transgenic organism
Insulin (modified E.Coli)
