Harnessing Biology Flashcards
What 5 steps are taken to select a particular feature in an organism?
1) Choose the individuals with the desired feature
2) Let only them reproduce
3) choose offsprings with that desired feature
4) Let those individuals reproduce
5) Repeat until a variety is produced with desired characteristic
Give examples of selective breeding in cows
- Most milk
- Produce more meat
Why do farmers use greenhouses to grow crops?
- Artificial heating
- Artificial lighting
- Additional carbon dioxide in the air
- Regular watering
What does the transparent material in greenhouses allow for?
Natural light which allows the effect of a ‘longer day’
What does burning fossil fuels do in greenhouses?
- Raises internal temperature, when external temperature is too low
- Produces carbon dioxide and water vapour
Why is water vapour needed in a greenhouse?
- Maintains a moist atmosphere
- Reduces water lost by transpiration
Organic fertilisers?
Made from faeces, straw and legumes such as clover
Inorganic fertiliser?
Compound formulated to yield a specific concentration of a particular ion
Disadvantages of organic fertilisers?
- Slow acting
- Bulkier
- May contain pests
Advantages of organic fertilisers?
- Improves soil structure
- Greater range of minerals
- Less cost to farmer
- Releases minerals over a longer period of time
Disadvantages of inorganic fertilisers?
- Can lead to eutrophication as fertiliser is insoluble
- Requires regular reapplication
Advantages of inorganic fertilisers?
- Fast acting
- Contents known
- Easy to apply
How are pests controlled?
- Pesticides
- Biological control
What do herbicides kill?
Plant pests
What do insecticides kill?
Insects
What do fungicides kill?
Fungi
What do molluscicides kill?
Molluscs (snails, slugs)
What controls whiteflies in a greenhouse?
A tiny parasitic wasp, encarsia
What is a feature of a biological pest?
NEVER eradicates the pest, only REDUCES to a level of no economic damage
Advantages of biological control?
- Only one cost for inital intro
- Pest specific
- Pests will not become resistant
- No effect on other animals
Disadvantages for biological control?
- Takes time to reduce pest population
- Not all population can be killed
- Expensive if re-populating is required
Advantages of pesticides?
- Reduces pest population instantly
- Can kill whole population of pests
Disadvantages of pesticides?
- Cost
- Not specific, will kill other animals
- Pests can become resistant
What is the anaerobic respiration equation in bread making?
Glucose —> Ethanol + Carbon Dioxide
Why are bubbles useful in bread making?
Carbon dioxide bubbles expand the dough, helping the rise
Why is high temperatures used in bread making?
So ethanol can evaporate out
What does the cooling jacket do in an industrial fermenter?
Removes heat energy, stopping fermenter overheating, and enzymes denaturing
What does the air filter do in an industrial fermenter?
Filters air coming in, maintaining sterile conditions
What do the stirred do in an industrial fermenter?
Keeps broth well stirred to oxygenate all the parts of the fermenter and prevents micro-organisms settling
What does the growth medium do in an industrial fermenter?
Contains all the necessary glucose, and amino acids for micro-organism growth
What does the super-heated steam do in an industrial fermenter?
Applied before fermenter is used, killing unwanted micro-organisms. Leaves water with no other residue
What bacteria is used in yogurt production?
Lactobacillus Bulgaricus
Why is milk pasteurised in yogurt making?
To kill bacteria
What temperature is the yogurt tainted at in the making process?
46°C
What does lactobacillus anaerobically respire to produce?
Lactic acid
What does the lactic acid do in yogurt making?
- Lowers pH, acing as a preservative
- Coagulates the milk proteins
- Gives texture and flavour
What are common species used for fish farming?
Salmon, and trout
What are the issues with putting several species in one pond in fish farming?
- Interspecific competition, species will compete for food and extinction
- Predation, carnivorous species will pray on other fish
What are the issues with putting too many fish in on e pond?
- Intraspecific competition, Larger fish will compete with smaller
- Infectious disease, Parasites and pathogens spread quicker
How does fish farming effect the environment?
Excess feed and waste cause eutrophication and a reduction in oxygen concentrations in water
What are the effects of deforestation?
- Leeching
- Soil erosion
- Evapotranspiration
What is leeching in deforestation?
Water is no longer taken up by plants, and can begin to ‘run off’ from the soil into rivers and lakes
What is soil erosion in deforestation?
Water run off may carry some of the top soil, causing water erosion. No plants in soil due to deforestation, therefore no roots holding soil in place
Why is top soil important?
Contains the most fertile, mineral ion rich materials
What is evapotranspiration in deforestation?
Process which water is transferred fro the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants, leading to droughts
