Key area 5- Food Production Flashcards
What must happen to our food yield if we have an increasing human population?
An increasing human population requires an increased food yield.
What can help increase food yield?
Fertilisers and pesticides.
What chemical is in fertilisers that helps increase crop yield?
Nitrates.
How can plants and animals that reduce crop yield be killed?
Through use of pesticides.
How are nitrates absorbed into plants?
Nitrates dissolved in soil water are absorbed into plants.
What can nitrates be used to produce?
Nitrates are used to produce amino acids which are synthesised into plant proteins.
How do animals obtain amino acids?
Animals consume plants or other animals to obtain amino acids for protein synthesis.
What can fertilisers be used for?
Fertilisers can be added to soil to increase the nitrate content of the soil.
How are algal blooms caused?
Fertilisers can leach into fresh water, adding extra, unwanted nitrates. This will increase algal populations which can cause algal blooms. Algal blooms reduce light levels, killing aquatic plants. These dead plants, as well as dead algae, become food for bacteria which increase greatly in number. The bacteria use up large quantities of oxygen, reducing the oxygen availability for other organisms.
What are genetically modified (GM) crops?
They are crops which have had their genetic material altered to enhance their characteristics.
What can genetically modified crops be used for?
To reduce the use of fertilisers.
What happens to pesticides that enter organisms bodies?
Pesticides sprayed onto crops can accumulate in the bodies of organisms over time. As they are passed along food chains, toxicity increases and can reach lethal levels.
What is bioaccumulation?
The build up of toxic substances in living organisms.
What is biological control?
It involves using a pest’s natural predator to control pest numbers.
What can genetically modified crops and biological control be used for?
They can be used as alternatives for pesticides.
