Use Of Biological Resources Flashcards
Yield definition
The amount of produce harvested
Poly tunnels and greenhouses can be used to increase the yield of certain crops. How can they control light?
Artificial lighting or shade covers
How can polytunnels control temperature
Heaters or ventilation
How can polytunnels control water
Irrigation systems
How can polytunnels control wind
Ventilation or fans
How can polytunnels tunnels control soil minerals
Fertilisers and minerals put in water
How can polytunnels control CO2
Wood burner to produce CO2 for photosynthesis
How do polytunnels control pollinators
Bee homes of safe insects
How can polytunnels control competitors and herbivore pests
By keeping them out of the polytunnels or using weed killer
What is the chemical control of pests
Using pesticides of weed killers to get rid of pests and weeds
What is biological control of pest
Putting predators that kill pests in or using parasites that weaken or cause disease in pests
What are the advantages of chemical control
It is specific
It can biodegrade or wash out
It is cost effective (until pests become resistant)
It is quick
What are the disadvantages of chemical control?
Can effect non target species Chemicals may get into food product People involved must wear suits as chemicals are toxic Could bio accumulate Not qualified as organic
What are the advantages of biological control
It is specific
It can reproduce by itself
Pests don’t become resistant
Natural can label as organic
What are the disadvantages of biological control
If too successful it can exhaust the food supply and switch prey
Not as quick
Does not completely remove pest
Control organism may become pest
May switch prey
Takes time for predators to become established.
Crop definition
Plants grown commercially for food on a large scale
What are intraspecific predators and interspecific predators?
IntRAspecific predators are predators within a species e.g. Salmon eating salmon
IntERspecific predators are different species e.g. Seals, sharks, birds or dolphins eating salmon
What is water quality affected by?
Oxygen and waste material
How is oxygen in water controlled in fish farms
In ponds or tanks water can be mechanically agitated or recirculated by pumps so more oxygen dissolves into the water
In cages in open water, water is oxygenated by natural tides and movement or plants (such as algae) that give off oxygen from photosynthesis
How is waster material in water controlled in fish farms and what are the dangers of waster material building up
Waste material accumulate from nitrogenous excretory products of fish(mostly ammonia). In too high levels and concentrations of ammonia it can be toxic and kill. It is controlled by water circulation
How is selective breeding used to improve fish yield
Superior individuals are selected for breeding to provide the next generation.
Entirely female fish stocks can be made as male fish become aggressive and their flesh quality decline when they get older.
How is feeding controlled to get a higher yield of fish?
Feeding is small, frequent and high in protein.
How are intraspecific predators controlled
Fish can be separated according to size or age in order to reduce competition and danger of bigger older fish eating small younger fish
How are interspecific predators controlled?
Nets prevent predators from getting inside the fish farm. Or measures are taken to kill the predators
What is fermentation
The production of ethanol when yeast, bacteria or other microorganisms break down sugars in the absence of oxygen
What else is produced in fermentation
Carbon dioxide
Why are barley grains needed to make beer?
They are broken down by enzymes to supply maltose and glucose. Extra sugars are sometimes added
What is used to add flavour? It also acts as a preservative
Hops
What is the role of yeast in the production of beer?
Yeast uses anaerobic respiration to ferment sugar to produce alcohol.
What is the word equation for anaerobic respiration in yeast?
Glucose –> energy (atp) + ethanol + CO2
What is the rough optimum temperature of yeast for respiration
15-25 degrees Celsius
What are restriction enzymes used to do?
They are used to cut out a section of DNA and making spaces in chromosomes for the DNA
What are ligase enzymes used for?
They are used to put DNA and chromosome segment together which is then put into a cell. (Joins DNA together)
What is a vector and what can they take the form of?
A vector can be a virus or a plasmid and it is a way to get genetically modified material transferred from a donor to a recipient
What is the definition of transgenic?
An organism that has undergone genetic modification and has had genes transferred from another unrelated organism. (Different species)
Describe how a plasmid vector creates insulin from e.coli bacteria.
Plasmid DNA has a but cut out which is replaced with an insulin gene. The plasmid is then put back into the ecoli cell which reproduces to make insulin clones.
Examples of genetically engineered plants
- golden rice genetically engineered to have more vitamin A taken from carrots
- frost resistant strawberries
- soy and corn modified for pest and herbicide resistance
What are the advantages of genetic engineering?
- can produce medical drugs
- produce crops with specific characteristics
- quicker than selective breeding
- increases crop yield
What are the disadvantages of genetic engineering
- high cost to poorer farmers
- ethical issues
- Unknown long term effects
- possible escape of genes into wild population
Describe the process of micropropagation
- an explant is removed from the parent plant
- the explant is sterilised to reduce the risk of contamination
- the sterile explant is placed in a tissue culture vessel containing a sterile growth medium
- the growth medium contains nutrients that encourage growth and the division of cells
- the plant is transferred to a fresh growth medium containing plant growth regulators. The stem, root and leaves then grow.
Micropropagation or tissue culture grows explants in vitro. What does in vitro mean?
A process taking place in a test tube, culture dish or somewhere outside a living organism
What are the advantages of micropropagation?
- can produce thousands of plantlets
- genetically identical
- disease free plant
- produces plants at any time of the year
What are the disadvantages of micropropagation?
- requires professionals and a sterile lab
- if one plant has or is susceptible to disease they all are.
Describe the process of animal cloning
An adult body cell is taken from a prize animal and an egg cell is taken from a different animal. The egg cell is enucleated and the nucleus from the adult body cell is placed into it. The embryo is then placed inside a surrogate mother which grows the embryo until it is born as a clone of the prize animal.
