B6.2 - Feeding The Human Race Flashcards
What is food security
Ability for population to have affordable food with sufficient quality and quantity
What may threaten food security
- increase in population
- changes in diet: people are becoming more reliant on meat based produce which requires a lot of energy to make than plant products
- climate change: environmental conditions such as lack of moisture in soil, reduces yield of produce.
- new pests and pathogens may evolve
What is something good about climate change that benefits crops
With increase of CO2 concentration in atmosphere, this actually helps plants to grow. Through photosynthesis, CO2 is often limiting factor so this reactant helps to maximise rates
How to increase food production
- fertilisers: helping land to remain fertile
- maximise photosynthesis: environmental conditions to maximise growth
- remove competition: any pests and pathogens that may kill plant like herbicides
- increase variation of crops: will be able to survive, adapt and reproduce a higher Yield
Intensive farming
Attempt to maximise food production by:
- by using fertilisers and pesticides
- maximise animal growth rate
- use machinery and less people
- large scale
- cheaper
Organic farming
Natural methods of crop production:- subsistence farming
- no artificial chemicals
- less animals and more time consuming
- done by hand/people
- small scale
- expensive
Sustainable food production
Whereby production of food can be continued indefinitely
(Advantages) of fish farming
- nets for fishes have big holes. This means only large and matured fish get trapped whereas smaller and young can still move and free to grow and increase in number, allowing not all fish to be caught
- these fishes are also bred together which increases their number and wild fish can recover: stopping extinction of species
(Disadvantages) of fish farming
As many fishes are kept very close to each other, possibility of diseases to spread is more frequent and fast.
Reducing fertilisers and pesticides
- natural fertilisers such as manure
- crop rotation: timing each crop to grow so soil has a chance to recover and no overgrazing which strips land of nutrients
- using biological control: using natural predators that eat pests and insects
Hydrophonics
Process where all plants are grown together with nutrient/ mineral rich water (solute based solutions)
- faster
- sustainable (water is reused and recycled)
- all grown together, same rate
- deliver high yields
- can control pests and diseases
BUT
- expensive
- energy consuming
- require lot of fertilisers
Selective breeding
Breeding plants or animals for particular/desired characteristics
Process of selective breeding
- Identity the organism with desired characteristics
- Choose parent with highest level of desired characteristics
- Breed from individuals
- Select best offspring and breed again
- Repeat for many generations
Disadvantages of selective breeding
- all focused towards one particular characteristics, so start becoming all identical and heavily similar.
- this results in reducing variation and decrease in gene pool
- as all clones, if new disease or environment conditions, will not be able to survive, adapt and reproduce and will die out- EXTINCTION
- also increases chances of inheritance diseases
Selective breeding vs genetic engineering
- Slower and over many generations / much faster in one gen
- less accurate / very accurate
Risks of genetic engineering
- emergences of new allergens
- all become very similar so reduce biodiversity
- crossing between dif breeds with disrupt balance of ecosystem
- seen unethical and fake: think it harms the animals
Genetic engineering with bacteria
- identify desired characteristics (e.g. insulin)
- remove from body to extract gene at early stages
- using PCR replicate the gene
- restriction enzyme cuts the DNA to get gene with exposed unpaired bases ‘sticky ends’ which will help to complementary base pair to plasmids
- same restriction enzyme used to cut open the bacterium plasmids
- using ligase enzyme will join together
- the vector + gene marker make a transgenic bacteria
- through UV light or environment conditions (temp and pH) will grow
- as bacteria replicates very quickly will produce high yield of desired characteristic
Using antibiotic resistance gene as marker
- follow same process
- when adding desired gene also add gene of antibiotics resistance
- will grow and replicate as normal
- but will know it is successful as the bacteria colonies will survive due to resistance and able to stand environmental conditions- will kill any other genes not supposed to be present
Genetic modification
Usually used for plants and animals
Examples of GM crops
Golden rice: taking the gene of beta-carotene, which helps the body to make vitamin A
BT corn: taking the gene of bacteria bacillus thuringiensis which codes to protein that is poisonous to pests. As the corn produces this, pests will die trying to feed on it
Genetic modification
-similar to GE but instead of using bacteria cells, uses plasmids, viruses and bacteria
- identify the gene for desired characteristics
- take gene from donor organism using restriction enzyme to cut exposed unpaired sticky bass ‘sticky ends’
- using same restriction enzyme, cut DNA of vector ( bacteria, plasmids, virus)
- the useful gene is spliced into DNA and combined DNA added to virus known as insertion
- new host begins to work and replicate as clones
Basic idea of GM and GE
Vector (bacteria, plasmid, virus) + gene marker (desired characteristic) = transgenic cell (cell with all)
How does GM help food security
- makes the yield larger
- better flavour food
- contains more nutrients
- stop disease and pest from killing plant
- more adapted to environment
- more time efficient
