Use of Biological Resources SLOP Flashcards
Describe how glasshouses and polytunnels can be used to increase the yield of certain crops
Glass provides greenhouse effect (traps heat); paraffin heaters provide heat and CO2 for increased photosynthesis; artificial lights mean crops can grow into the night and out of season; pests can be controlled easily; can easily control nutrition of crops being grown; protection from disease; control how much water is supplied to plants
Describe the role of fertiliser in increasing crop yields
Can control exactly what mineral ions, e.g. magnesium and nitrates, the plants are getting; constant, effective growth
State a danger of fertiliser use on fields of crops
Can leach into water ways and cause eutrophication
Why might we want to use chemical pesticides?
Kill pests and increase crop yields
Give three advantages of biological control over pesticides
No bioaccumulation (building up of toxic chemicals in food chain); specific to certain pests (exploits natural predator-prey relationships); no need to reapply (lowers cost compared to pesticides); no resistance forms; longer lasting
State two commercial products that yeast can be used to make industrially
Bread, beer
What species of bacteria can be used to make yoghurt? How does this work?
Lactobacillus; respires anaerobically and ferment lactose in milk to produce lactic acid; lactate coagulates milk proteins and causes milk to thicken
Write a word equation for the anaerobic respiration of yeast
Glucose –> Ethanol + carbon dioxide
Suggest two products that could be produced on a large scale using a fermenter
Insulin, penicillin (antibiotic)
Why must conditions in a fermenter remain aseptic?
To prevent infection, disease or contamination of product
Why might sterile air be pumped into a fermenter
To allow the bacteria to respire aerobically, providing energy for growth; sterility of air means less chance of contamination
Why are there paddles in a fermenter?
To agitate the fluid, evenly distributing oxygen and nutrients
Why might a fermenter be surrounded with a water jacket?
To cool the tank and ensure optimum temperature is achieved for enzymes
What chemical could be used to test whether yeast are respiring anaerobically?
Bubble gas produced into limewater; turns cloudy
Fish are a good source of which major nutrient?
Protein (fish diet can be carefully controlled in a fish farm)