food production 3.5

Question 1

how do you get more food

Answer 1

by increasing the crop yield (how much food can successfully be harvested

Question 2

what things can increase the crop yeild

Answer 2

fertilisers and pesticides

Question 3

explain what a fertiliser is and what does it do

Answer 3

provide chemicals like nitrates which help plants to make proteins which helps them to grow.

Question 4

explain what a pesticide is and what it does

Answer 4

they kill plants and animals(pests) that damage crops so that the crop yield is increased

Question 5

explain the nitrogen cycle

Answer 5

Nitrates dissolved in soil water are absorbed in plants
Nitrates are used to produce amino acids which are synthesised (built up) into plant proteins
Animals consume plants or other animals to obtain amino acids for protein synthesis (to make their own proteins)

Question 6

what are the 2 types of fertilisers and give exapmles/describe them

Answer 6

chemical-chemical fertilisers add nitrates through soil water which plants absorb through their roots
natural-ploughing clover into a feild-growing clover then plowing it back into the soil .the decomposed clover releases nitrogen into the soil for other plants to use

Question 7

problems with fertilisers

Answer 7

leaching

Question 8

explain leaching

Answer 8

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.

Question 9

problems with pesticides

Answer 9

bioaccumulation

Question 10

explain bioaccumulation

Answer 10

Pesticides sprayed on to crops can accumulate in the bodies of organisms over time As they are passed along the food chains, toxicity increases and can reach lethal levels

Question 11

alternatives to pesticides

Answer 11

biological control, genetically modified crops

Question 12

explain biological control

Answer 12

biological control is when an organism is added to control a particular pest. there is 3 types-predators, parasite and pathogen(disease)

Question 13

explain GM crops

Answer 13

when the DNA of a plant has been modified to protect them from pests, some crops have been modified so that they are palatable to their pests

Question 14

alternative to fertilisers

Answer 14

Genetically modified (GM) crops can be used to reduce the use of fertilisers as they grow larger without added nitrates