Practise explaining crop yield, pest control and yeast fermentation using glasshouse investigations, graphs, apparatus choices and food-production contexts.
Farmers can increase their crop yield by growing crops in a temperature controlled glasshouse.
Explain how increasing the temperature can result in an increase in crop yield.
Farmers sometimes use a type of heater that burns gas or oil to raise the temperature of their glasshouse to improve crop yield.
Explain why they use this type of heater to improve crop yield.
Some farmers also add chemical fertilisers to their crops in a glasshouse.
Different minerals are added to chemical fertilisers. Explain one mineral that should be added to these fertilisers.
Using the recommended amount of fertiliser on a crop increases crop yield. Some farmers think that adding extra fertiliser will give an even greater crop yield.
Give a reason why adding extra fertiliser does not result in an even greater crop yield.
Golden rice is an example of a genetically modified plant.
Golden rice has been given a gene to make a substance called carotene.
This gene was taken from daffodil plants.
Chemical pesticides can be used in rice fields to kill insect pests.
Scientists investigate the effect that spraying pesticides in a rice field has on three types of organism.
The three types of organism investigated are:
- insect pests
- carnivorous beetles (predators of insect pests)
- lizards (higher trophic level predators)
The scientists count the number of each type of organism in the rice field.
The scientists then spray the field with pesticide.
The number of each type of organism in the field are then counted every three months for a year.
The table shows the scientists' results.
These are the scientists' results.
Comment on the effects on the numbers of different organisms of spraying pesticides in a rice field.
State two reasons why using biological control is better for the environment than using chemical pesticide.
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