KA3.5 - Food Production

Question 1

What must happen to food yield due to the rapidly increasing human population?

Answer 1

Food yields must increase.

Question 2

Increasing food yields involves use of fertilisers and …

Answer 2

Pesticides

Question 3

Nitrogen is an essential element in plants and animals as it is used to produce … … which are synthesised into plant proteins.

Answer 3

Amino acids

Question 4

Describe the steps of the nitrogen cycle?

Answer 4

1. A plants source of nitrogen are the nitrates dissolved in the soil water.
2. These nitrates are absorbed through the root hair cells into the plant.
3. The nitrates are then used to produce amino acids which are synthesised into plant proteins.
4. Animals then consume the plants and obtain amino acids for protein synthesis to produce animal proteins.
5. Higher up the food chain, animals consume other animals to obtain amino acids for protein synthesis.

• Fertilisers can be added to the soil to increase the nitrate content.

Question 5

Fertiliser leaching occurs when fertilisers used on farmland enter …

Answer 5

Fresh water (rivers and lakes)

Question 6

A rapid increase in algae population due to fertilisers is called …

Answer 6

Algal bloom.

Question 7

Explain how fertiliser leaching happens and the impact of algal bloom?

Answer 7

1. Fertilisers leach into fresh water adding extra, unwanted nitrates.
2. The nutrients in fertilisers allow rapid algal growth resulting in an algal bloom.
3. This reduces light levels resulting in death of aquatic plants.
4. The dead plants and dead algae become food for bacteria which increase in number greatly.
5. The bacteria use up large quantities of oxygen reducing oxygen availability for other organisms.

Question 8

Genetically modified crops can be used to … fertiliser and pesticide use.

Answer 8

Reduce. They are able to grow better and without pesticide, reducing those chemicals impact upon the environment.

Question 9

Pesticides are chemicals which …

Answer 9

pesticides are chemicals which kill plants and animals which have the potential to reduce crop yield.

Question 10

Describe the negative effect of pesticide bioaccumulation.

Answer 10

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

Question 11

Biological control is the use of a … as a way of controlling pest species.

Answer 11

natural predator. Biological control is the use of a natural predator as a way of controlling pest species.

Question 12

Explain the risk of using biological control?

Answer 12

They may become pests themselves or stop being effective.