9 - Use of Biological Resources Flashcards
Describe how to artificially create ideal conditions for photosynthesis
- Greenhouses trap in heat to keep plants warm (farmers can also use heaters)
- Farmers can increase the amount of CO2 by using a paraffin heater
- This increases the amount of photosynthesis for the plants so the crop yields will be higher
How do farmers give plants enough nutrients?
By using fertilisers
Why is pest control useful?
- Stops pests from eating plants
- Pesticides (chemical) can be poisonous to humans too and kill other wildlife too
- Biological control is using another organism to prey on the pests
- Biological control can have longer lasting effects as the new organisms can adapt and become pests themselves or kill too many organisms (e.g. cane toads in Australia)
Describe the process of making yoghurt
- Sterilise equipment
- Pasteurise the milk (72*C for 15 seconds) to kill any microorganisms
- Lactobacillus bacteria is added and the mixture is incubated (40*C) in a fermenter
- The bacteria ferment the lactose sugar in the milk to form lactic acid causing the milk to clot and solidify to yoghurt
- Flavours are often added
What is fermentation?
When microorganisms break sugars down to release energy - usually by anaerobic respiration
How are microorganisms grown?
- In fermenters
- Can be used to make penicillin or insulin
How do fermenters work?
- Nutrients needed by the microorganisms for growth are provided in the liquid culture medium
- The pH is monitored and kept at the optimum level for the enzymes
- Temperature is kept at the optimum temperature
- Vessels are sterilised between uses with superheated steam that kills unwanted microbes. having aseptic conditions increases the yield
Why is it good to have aseptic conditions?
Having aseptic conditions increases the yield of the product as the organisms aren’t competing with other organisms. It also means the product is not contaminated
How do fermenters work?
- Nutrients needed by the microorganisms for growth are provided in the liquid culture medium
- The pH is monitored and kept at the optimum level for the enzymes
- Temperature is kept at the optimum temperature
- Vessels are sterilised between uses with superheated steam that kills unwanted microbes
- Oxygen for respiration can be added by pumping sterile air
- Microorganisms are kept in contact with fresh medium by paddles that circulate the medium around the vessels so there is equal access to the nutrients
Why is it good to have aseptic conditions?
Having aseptic conditions increases the yield of the product as the organisms aren’t competing with other organisms. It also means the product is not contaminated
Describe how to make beer
- Made from grain (usually barley)
- Allow to germinate for a few days so the starch in the grains is broken down into sugar by enzymes
- The grains are dried in a kiln (called malting)
- The malted grain is mashed up and water is added to produce a sugary solution with lots of bits and is then sieved
- Hops are added to give a bitter flavour
- Yeast is added
Describe how to make beer
- Made from grain (usually barley)
- Allow to germinate for a few days so the starch in the grains is broken down into sugar by enzymes
- The grains are dried in a kiln (called malting)
- The malted grain is mashed up and water is added to produce a sugary solution with lots of bits and is then sieved
- Hops are added to give a bitter flavour
- Yeast is added and the mixture is incubated
- The yeast ferments the sugar into alcohol
- The rising concentration of alcohol in the fermentation mixture due to anaerobic respiration eventually kills the yeast which slows down fermentation
- The beer is drawn off through a tap
- Clarifying agents can be added to remove particles and make it clearer
- The beer is pasteurised to kill any yeast left and so it keeps better
- Beer is sold
Describe how to make beer
- Made from grain (usually barley)
- Allow to germinate for a few days so the starch in the grains is broken down into sugar by enzymes
- The grains are dried in a kiln (called malting)
- The malted grain is mashed up and water is added to produce a sugary solution with lots of bits and is then sieved
- Hops are added to give a bitter flavour
- Yeast is added and the mixture is incubated
- The yeast ferments the sugar into alcohol
- The rising concentration of alcohol in the fermentation mixture due to anaerobic respiration eventually kills the yeast which slows down fermentation
- The beer is drawn off through a tap
- Clarifying agents can be added to remove particles and make it clearer
- The beer is pasteurised to kill any yeast left and so it keeps better
- Beer is sold
Describe an experiment to show the respiration rate of yeast depending on conditions
- Mix together sugar, yeast and distilled water and add to a test tube
- Attach a bung with a tube leading to a second test tube of water
- Put the yeast tube in a water bath at a certain temperature
- Count how many bubbles are produced in 1 minute
- You could also use a gas syringe
- This can be used to calculate the rate of CO2
- Repeat at different temperatures up until the optimum temperature
What is selective breeding?
Mating two organisms with desirable characteristics to increase the chance of the offspring inheriting these characteristics
- Yield
- Health/disease resistance
- Animals = temperament/speed/fertility
- Plants = attractive flowers, nice smells
How does selective breeding increase the productivity of cows?
- High meat yield
- Continued over many generations to increase the whole cattle
How does selective breeding increase the number of offspring in sheep?
- Female sheep who produce lots of offspring are bred more
How does selective breeding increase the crop yield
- e.g. tall wheat plants have good grain yield but are damaged easily by rain and wind
- They are bred with dwarf wheat plants who can resist rain and wind but have a low yield
How does selective breeding increase the crop yield
- e.g. tall wheat plants have good grain yield but are damaged easily by rain and wind
- They are bred with dwarf wheat plants who can resist rain and wind but have a low yield
Describe how and why fish are farmed in the sea
- The fish are kept in cages in the sea to stop them using as much energy swimming about
- The cage also protects them from preditation
- The fish are fed pellets that are carefully controlled to maximise the amount of energy they get meaning they will grow quicker and bigger
- Young fish are kept in special tanks to make sure as many survive as possible
- Keeping the small fish away from the big fish means they won’t be eaten and will have enough food
- Fish kept in gages are more prone to disease and parasites (e.g. sea lice which can be treated with pesticides or biological control of wrasse)
- The fish can be selectively bred to produce less aggressive, faster-growing fish
What is intraspecification?
When organisms eat individuals of the same species
What are the conditions for farming fish in tanks?
- Water can be monitored for temperature, pH and oxygen level
- Control the amount of food and the right type of food
- Water can be removed and filtered to get rid of waste which keeps it clean for the fish
What is the role of a restriction enzyme?
To recognise specific sequences of DNA and cut DNA at these points
What is the role of a ligase enzymes?
Used to join two pieces of DNA together
What is a recombinant DNA?
Two different bit of DNA stuck together
What is genetic engineering?
Moving useful genes from an organism’s chromosomes into the cells of another
Describe how vectors are used in genetic engineering
-
What is a vector?
Something that is used to transfer DNA into a cell
There are two sorts - plasmids and viruses
What are plasmids?
Vectors that are small, circular molecules of DNA that can be transferred between bacteria
What are viruses?
Vectors that insert DNA into the organism they infect
Describe to process of genetic engineering
- The wanted DNA is but out by a restriction enzyme
- The vector DNA is cut open using the same restriction enzyme
- The vector DNA and DNA being inserted are mixed together using ligase enzymes
- The ligases join the two pieces of DNA together to produce recombinant DNA
- The recombinant DNA (the vector with the new DNA) is inserted into other cells (e.g. bacteria)
- the cells can now use the inserted gene to make the protein wanted
- e.g. bacteria containing the gene for human insulin can be grown in huge number in a fermenter to produce insulin for people with diabetes (the are transgenic)
What are viruses?
Vectors that insert DNA into the organism they infect
What does transgenic mean?
The cell contains genes transferred from another species
What does transgenic mean?
The cell contains genes transferred from another species
Why are plants genetically modified?
- To increase food production
- Making crops insect-resistant so less pesticides are used
- Making crops herbicide-resistant means farmers can spray their crops to kill weeds without affecting the plat`
Why are plants genetically modified?
- To increase food production
- Making crops insect-resistant so less pesticides are used
- Making crops herbicide-resistant means farmers can spray their crops to kill weeds without affecting the plant`
How can plants be cloned?
Micropropagation
Describe the process of micropropagation
- A desirable plant is chosen and small pieces are taken from the tips of the stems and the side shoots (called explants)
- It is sterilised
- The explants a placed in a petri dish containing a nutrient medium (which has all the nutrients needed for growth)
- The cells in the explants divide and grow into a small plant
- The small plants are taken out od the medium, planted in soil and put in glasshouses so they develop into plants that are genetically identical to the original plant
Describe how to clone a mammal
- The nucleus of the animal is removed creating an enucleated cell
- A diploid nucleus (with a full set of chromosomes) is inserted to replace the nucleus
- The cell is stimulated by an electric shock so it starts dividing by mitosis
- The cell is inserted into a surrogate mother
What are uses/advantages of cloning?
- Animals who produce medicine in their milk can be cloned
- Animals (pigs) have organs suitable for organ transplantation to humans
- Useful genetic characteristics are always passed on which doesn’t always happen in reproduction
What are some risks/disadvantages of cloning?
- It is a new scientific idea that people are not used to so they don’t agree
- Cloned animals may not be as healthy as normal and often die
- Expensive
- Time consuming
- Difficult and rarely works
