Use of Biological Resources Flashcards
How can glasshouses and polythene tunnels be used to increase the yield of certain crops?
Conditions such as temperature, carbon dioxide and light can be controlled so that there are no rate-limiting factor. This ensures a maximum yield.
What are the effects of increasing carbon dioxide and temperature in glass houses?
- Increasing amount of CO2 increases crop yield as there is more reactant= more product
- increasing the temperature increases crop yield as enzymes are at optimum temperature so the rate of photosynthesis increases.
- more photosynthesis= more glucose = more energy for growth= higher yield.
Why are fertilisers used to increase crop yield?
They contain minerals that plants require (e.g. NKP)
Nitrates= amino acids–> proteins–> growth
Phosphates= needed for respiration and growth as cells need phosphorus to make DNA and cell membranes.
Potassium= enzymes need potassium for respiration and photosynthesis.
What are the reasons for pest control and biological control?
Pests can eat/damage crops so they cannot be sold= less profit for farmers.
Advantages of pest control?
Ensures crop yield is maximum
Doesn’t damage the actual crop
Fast and accurate
Instant results
Disadvantages of pest control
Can harm other wildlife
Killing pests may affect diversity
Pests can become immune
Can leech into soils and pollute surrounding rivers and habitats.
What are the positives of biological control
Cheap No harm to other species Self regulating Lasts longer Specific No resistance No effect on food chains
What are the disadvantages of biological control
May effect biodiversity or enter wildlife
What is the role of yeast in beer production?
Yeast is required as it converts sugar to ethanol and carbon dioxide when it respires anaerobically.
Describe an experiment to investigate carbon dioxide production by yeast in different conditions
1) place yeast in a glucose solution in a test tube and add a layer of oil on top to prevent yeast from respiring aerobically.
2) place test tube in water baths of different temperatures
3) collect gas coming off in a gas syringe and compare depending on temperature.
Role of lactobacillus in yoghurt production
When lactobacillus bulgaricus respires anaerobically, it produces lactic acid, which denatures the protein and cusses it clump together= yoghurt
Why are aseptic precautions required in a fermenter
Needed to prevent the entry of microbes that would use up the nutrients and O2, effect the production and contaminate it.
Need for nutrients in fermentor?
To allow rapid growth of cells
Need for optimum ph and temperature in fermentor
Helps enzymes work at their best ability.
Need for oxygenation in fermenters
Allows aerobic respiration to occur
Need of Agitation in fermentor
Paddle wheels agitate and spread out the reactants so that they are not concentrated in one area.
What methods are used to farm large numbers of fish to provide a source of protein?
Water quality: water is filtered:gets rid of waste (e.g. faces and leftover food) –> avoids pollution.
Intraspecific: fish separated by age and gender, regularly fed and given adequate room.
Interspecific: fish in tanks and also nets.
Disease: water is changed, surroundings sterilised and small amounts of fish kept together.
Quality and frequency of feeding: fed in small amounts with nutrient rich food.
Selective breeding: fish with strong characteristic are bred together.
How can plants and animals with desired characteristics be made?
Selective breeding.
Use of restriction enzymes
Used to cut DNA at specific sites
Ligase enzymes
Used to join or stick DNAs together.
What cam plasmids and viruses act as and how
Vectors
They take up pieces of DNA and inset this recombinant DNA into other cells.
What does recombinant mean?
When DNA fragments are inserted into a vector
How can large amounts of human insulin be produced?
From GM bacteria
The insulin causing gene is taken from a cell using a restriction enzyme and is the placed into a bacteria’s DNA. Bacteria is then put into a fermentor where conditions are optimum for it to replicate many times= a lot of insulin.
Potential for producing GM plants to improve food production
- Increases plant resistance to infectious diseases caused by fungi, bacteria and viruses
- increases plant resistance to pests
- give plants immunity to chemical herbicides
