key area 5 - food production

Question 1

what is current intensive farming?

Answer 1

this inludes growing high yeild crops and can involve the use of fertilisers and pesticides. fertilisers provide chemicals suchas nitrates which increase crop yeild. plants and animals which reduce crop yeild can ve killed by pesticides.

Question 2

what current chemical solutions do farmers use to increase food production?

Answer 2

1. fertilisers. nitrates are an essential for plant growth. nitrates dissolve in soil water and are absorbed into plants by plant roots.
2. pesticides. pesticides are chemicals that are used to kill pests that would decrease plant growth

Question 3

what are nitrates used for by plants ?

Answer 3

nitrates are used by plants to make amino acids which are synthesised into protein in the plants.

Question 4

what is a problem fertiliser can cause?

Answer 4

1. fertiliser can leach into fresh water adding unwanted nitrates.
2. this will increase algal populations which can cause algal blooms
3. algal blooms reduce light levels killing aquatic plants below them
4. these dead plants as well as dead algae become food for bacteria which increase greatly in number.
5. the bacteria use up large quantities of oxygen, reducing the oxygen availability for other organisms
6. other organisms die

Question 5

suggest an alternative to using fertiliser

Answer 5

genetically modified crops, gm crops can be used to reduce the use of fertilisers.

Question 6

suggest a negative effect of the excessive use of pesticides

Answer 6

bioaccumulation - pesticides sprayed onto crops csn accumulate in the bodies of organisms over time, as they are passed along food chains, toxicity increases and csn resch lethal levels

Question 7

suggest an alternative to the use of pesticides

Answer 7

1 biological control i.e a predator or parasite is introduced into the crop to eat the insect pests
2 use genetically modified crops