Food production Flashcards
What is a food yield?
The amount of food grown from crops.
What is biological control?
Using living things to help control pests.
What are pesticides?
Chemicals that kill animals or weeds that harm crops.
What is genetically modified crops?
Crops that have had new genes added to them artificially to give them improved characteristics.
What are the advantages of fertilisers?
Increases crop yield.
What are the disadvantages of fertilisers?
Can leach into fresh water.
What are the advantages of pesticides?
Prevents crop damage.
What are the disadvantages of pesticides?
Bioaccumulation in food chains.
What are the advantages of GM crops?
Can increase yields and protect from pests.
What are the disadvantages of GM crops?
Expensive.
What are the advantages of biological control?
No chemicals required.
What are the disadvantages of biological control?
Difficult to manage.
How do fertilisers help plants grow?
Fertilisers provide chemicals such as nitrates which help increase crop yield. Nitrates are used to produce amino acids which are used to make plant proteins.
What happens if fertilisers get into fresh water?
Fertilisers can leach into fresh water, adding extra, unwanted nitrates. This can result in the death of fish living in the water.
How do the fish die from fertilisers leaching into the water?
1) Fertilisers leach into fresh water.
2)There is an increase in algal populations, this is known as algal bloom.
3)Algal blooms reduce light levels, killing aquatic plants.
4)The dead plants become food for bacteria.The bacteria increases greatly in number.
The bacteria use up large quantities of oxygen, reducing the oxygen availability for other organisms such as fish.
What is bioaccuulation?
Pesticides sprayed onto crops can acccumulate in the bodies of organisms over time. As they are passed along food chains toxicity increases and can reach lethal levels. This is known as bioaccumulation.
