Unit 5 Flashcards
What does an increasing human population require
An increases food yield
An increase in food production can…
Involve the use of fertilisers and pesticides
Fertilisers provide…
Chemicals such as nitrates which increase crop yield
What can plants and animals that reduce crop yield be killed by?
Pesticides
What are nitrates dissolved in
Nitrates Dissolved in soil water are absorbed into plants
WhT are nitrates used for
Nitrates are used to produce amino acids which are synthesised into plant proteins.
What do animals consume
Plants or other animals to obtain amino acids for protein synthesis.
Fertilisers can be added to soil to…
Increase the nitrate content of the soil
4 marks
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.
Genetically modified crops 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 can happen when pesticides are 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 the build up of toxic substances known as
Bioaccumulation
What can be used as alternatives to pesticides
Biological control and GM crops
