Life on Earth - 3.5 Food production Flashcards
(17 cards)
Increasing human population requires ?
An increased food yield
this can involve the use of fertiliser and pesticides
What does fertiliser provide ?
Chemicals such as nitrates, which increase crop yields
Plants and animals that reduce crop yields can be killed by ……… ?
Pesticides
What substances dissolved in soil water are absorbed into plants ?
Nitrates
What are nitrates ?
Nitrates are used to produce amino acids which are synthesised into plant proteins
Why do animals consume plants or other animals ?
to obtain amino acids for protein synthesis
What can be added to soil to increase the nitrate content of the soil ?
Fertilsers
What can fertiliser leach into ?
Fresh water
adding extra
unwanted nitrates
Fertiliser can leach into fresh water, this will increase ?
algal populations which can cause agal blooms
What do algal blooms reduce ?
Light levels
Killing aquatic plants
Dead aquatic plants and dead algae, become food for ….. ?
Bacteria which increase greatly in number
What does the bacteria use up large quantities of …. ?
Oxygen + reducing the oxygen available for other organisms
What can genetically modified (GM) crops be used for ?
reduce the use of fertiliser
Pesticides sprayed onto crops can ?
Accumulate in the bodies of organisms overtime
The build-up of toxic substances in living organisms is known as ?
Bioaccumulation
Bioaccumulation is passed along food chains, toxicity increases and can reach ?
Lethal levels
The use of Biological control and genetically modified crops are alternatives to ?
The use of pesticides
