B6.2 - Food Security Flashcards
describe 5 factors affecting levels of food security
- increasing human population
- changing diets in wealthier population
- new pests and pathogens
- climate change
- sustainability and cost of agricultural inputs
why does an increasing human population affect food security?
more people = more food needed
how does changing diets in wealthier countries affect food security?
- each person wants good food (ie. imported), or more meat (less security)
how does climate change affect food security?
- global warming causes more droughts
- higher desertification
- unpredictable rain
positives of higher CO2 levels in the air?
- they may increase crop yields (for photosynthesis)
how does increasing agriculture costs affect food security?
- more expensive to grow food/store/distribute
- so price is too high for other people to afford
define food security
the ability of human populations to access food of sufficient quality and quantity
state 5 agricultural solutions to the demands of the growing human population
- hydroponics
- biological control
- gene technology
- fertilisers
- pesticides
describe hydroponics
- growing crops by replacing soil with mineral solution
- can control growth by changing temperature
positives of hydroponics
- mineral solution can be recycled
- plants grow quickly
- more plants can grow n the same space (can be stacked on top of each other)
negatives of hydroponics
- very expensive (set-up costs, constant power required, maintenance costs)
- susceptible to waterborne diseases
describe biological control
- release a natural predator
- to kill pests where a crop is being grown
disadvantages of biological control?
- may affect other organisms in the food web
- predator may be hard to control
advantages of biological control
is an alternative to pesticide, so an organic farming method
how would gene technology solve the demands of a growing human population?
produce them to have better yields (disease resistant, pest resistant)
how do herbicides and pesticides solve the demand of a growing human population?
- remove animals that eat crops
- herbicides get rid of competing crops
negatives of pesticides and herbicides?
- reduces biodiversity
terrible answer tbh -> you should know what you should write
- pesticides may pass up the food chain
difference between intensive farming and organic farming?
organic = avoid use of chemicals, smaller yields
intensive = main goal is maximum yield (ie. caged animals = maximum energy for mass and not movement)
define sustainable food production
producing food that can be continued for an indefinite period of time
negatives of fish farming? (3)
- disease spread quickly
- expensive
- water quality may be bad as faeces pollutes water
what is selective breeding?
when humans breed certain plants or animals which have desirable characteristics (ie. may use it to increase crop yield)
3 step process in which selective breeding occurs?
1) select individuals with desirable characteristics + breed together
2) breed best offspring
3) repeat over many generations
disadvantages of selective breeding?
- reduces gene pool (vulnerable to new pathogens)
- increased chances of inherited diseases
- unforeseen physical problems (too heavy to walk)
how has selective breeding affected food plants?
- wheat has large ears
- generally in a way to increase crop yield
- wheat ripens at the same time
define genetic engineering
a process which involves modifying the genome of an organism to introduce desirable characteristics
state the steps carried out to genetically engineer an organism
1) a gene is identified for the desired characteristic
2) gene is cut from the rest of DNA by restriction enzymes
3) DNA taken from bacterium (ie. plasmid/ring of DNA)
4) same restriction enzyme cuts open the plasmid
5) ligase enzymes rejoin cut out gene and plasmid ring at sticky ends
6) modified vector is placed into a bacterium
7) bacteria then reproduces through binary fission
define the term ‘transgenic bacteria’
bacteria which have DNA from another organism
when producing insulin from bacteria:
a) what gene is taken from humans
b) how is it produced?
a) insulin gene removed from human DNA
b) transgenic bacteria reproduce + produce insulin (a lot of it)
what is used to see if cells incorporate foreign genes?
- insert antibiotic resistant gene, if cells survive after adding antibiotics, gene has been taken up
- insert gene markers (like glow in the dark ones)
what is the term used to describe the organism in which the desired gene is removed from?
donor organism
what is the term used to describe the organism n which the gene is inserted into?
host organism
compare selective breeding to genetic engineering
selective breeding - slow process (several generations)
- may not be exact
genetic engineering - a specific gene can be targetted (more exact)
- both are used to change the characteristics of an organism
explain some benefits of using gene technology in modern agriculture (4)
- can have crops with desired characteristics
- improve yields (help with population growth)
- plants can produce their own pesticides (no need for farmer to spray)
- crops can have vitamins (ie. golden rice) - usually hard to obtain
explain some risks of using gene technology in modern agriculture (4)
- do not know full effects of GM on human health
ie. allergens - could create ‘super weeds’ and ‘pests’, as they destroy all the other ones through making herbicides/insecticides
- could disrupt ecosystems
- may be seen as unethical
define what biotechnology is
the process of manipulating genes (can be using biological processes), to produce a product
what is a biotechnological solution to the demands of the growing human population?
genetic modification
give two products of genetic modification and explain how they’ve been changed
- golden rice (has gene from daffodil to produce beta-carotene), the body then uses it to make vitamin A
- Bt corn (has gene from bacteria which produces a poisonous protein that kills insects)
difference between genetic modification and genetic engineering?
genetic modification is used for plants + animals
genetic engineering is for bacteria
how do you genetically modify an organism?
- same steps as genetic engineering
- but vector is inserted to organisms’s cell (ie. a virus)
- so that modified DNA is copied
- and then replicated in all the other organisms’s cells
