3.5 Food Production Flashcards
What is happening to the human population?
Increasing rapidly
What does the increasing population require?
Increasing quantity of food
Why must crop yield (how much is produced per unit area) be increased?
To prevent food shortages
What are two methods of increasing yield?
Fertilisers and pesticides
What do fertilisers do?
Add nutrients to the soil, to be taken up by the plants
What is one of the main nutrients provided by fertilisers?
Nitrates
Why are nitrates required by plants?
To produce amino acids
What are amino acids used to form?
Proteins
Why do animals need to eat plants (or animals)?
To obtain amino acids, to make there own proteins
What is the loss of nutrients from fertilisers in to fresh water known as?
Leaching
What can happen if fertilisers leach into water?
An algal bloom can form
How does leaching cause algal blooms?
Adds additional nutrients to the water, meaning algae can reproduce rapidly
How does algal blooms affect the water
Cover the surface of the water and block out the light
What does algae covering the surface do to organisms in the water?
Reduced light availability
Aquatic plants can’t grow so they die
What happens to the dead plant material and dead algae?
Will be consumed by bacteria
Which reproduce quickly
What does bacteria use up within the water making other organisms die?
Oxygen
What is an alternative to fertilisers?
Genetically Modified (GM) Crops
What are pesticides used for?
Kill or prevent pests on plants
Which can reduce the yield on crops
What is bioaccumulation?
When pesticides accumulate in the body of organisms in food chains over time
What is the risk of pesticides?
As they are passed thorough food chain they can reach lethal levels
What is an alternative to pesticides?
Biological control
Genetically modified crops
