key area 4:food production

Question 1

what are 3 commercial uses of plants?

Answer 1

raw materials,food and medicine

Question 2

what do fertilisers do to plants?

Answer 2

they provide chemicals such as nitrates which can increase crop yield

Question 3

how are the nitrates in fertilisers absorbed into plants?

Answer 3

they are dissolved into water to make it easier to be absorbed

Question 4

what are nitrates used for in plants?

Answer 4

they are used to produce into amino acids for protein synthesis

Question 5

why do animals eat these plants and or other animals?

Answer 5

to obtain these amino acids for protein synthesis

Question 6

what are other farming methods?

Answer 6

spreading manure and growing clover to plough back through the soil

Question 7

how do algal blooms occur?

Answer 7

algal blooms happen when fertilizers leach into fresh water which adds unwanted extra nitrated in the water

Question 8

what are the first 3 factors of an algal bloom?

Answer 8

1.additional,unwanted nitrated are added to fresh water

2.alagae utilises the additional nitrates to build protein and grow,leading to algal blooms

3.algal blooms reduce light levels,killing aquatic plants as they cant use light to photosynthesise and make glucose

Question 9

what are the last 3 factors of an algal bloom?

Answer 9

4.these dead plants ,as well as dead algae become food for bacteria which increase greatly in numbers

5.the bacteria use up large quantities of oxygen,reducing the oxygen availability for other organisms

6.the population of other marine organisms will decline

Question 10

what are chemical pesticides?

Answer 10

they are substances that are sprayed onto crops to kill organisms that can reduce plant growth such as weeds,insects and fungi

Question 11

what is bioaccumulation?

Answer 11

pesticides sprayed onto crops can accumulate in the bodies of organism over time as they are passed along food chains,toxicity increases and can reach lethal levels .

Question 12

what are 2 alternatives to fertilizers?

Answer 12

genetically modified organisms and biological control

Question 13

explain genetically modified organisms

Answer 13

this means that they have genes from other organisms to improve their characteristics,eg they can be more resistant to disease or toxic organisms ,which may reduce the need for intensive farming

Question 14

explain biological control ?

Answer 14

this is an alternative to pesticide and involves using one pieces which is a natural predators of a pest .this can keep pest numbers down without the need for chemicals.eg using ladybugs to control aphid population