Edexcel GCSE Biology 1BI0
Key Concepts in Biology
Cells and Control
Genetics
Natural Selection and Genetic Modification
Health, Disease and the Development of Medicines
Plant Structures and Their Functions
Animal Coordination, Control and Homeostasis
Exchange and Transport in Animals
Ecosystems and Material Cycles
Natural Selection and Genetic Modification
Benefits and risks of GM organisms
- 3 things to know
- Paper 1
Overview
Crops given the Bacillus thuringiensis toxin gene and their advantages, pest resistance and other concerns about GM crops, the cost of GM seed, fertilisers and how run-off kills fish, biological control and its advantages and disadvantages, and calculating the percentage increase in yield.
What you need to know
Answer each one before you reveal it.
Give two advantages of growing insect-resistant crop plants.
Explain why growing insect-resistant crops may harm other wildlife less than spraying insecticide does.
Questions from this subtopic
Each one with the model answer underneath.
- 1
What is a genetically modified crop?
Model answer
It is a crop plant whose genome has had a gene added so that it shows a useful new characteristic.
- 2
Which bacterium supplies the gene used to make crop plants resistant to insect pests?
Model answer
Bacillus thuringiensis.
- 3
Explain how a gene from Bacillus thuringiensis protects a crop plant.
Model answer
The plant's cells make the bacterial toxin in their tissues, so insect larvae that feed on the crop are poisoned and die.
- 4
Give two advantages of growing insect-resistant crop plants.
Model answer
Less of the crop is eaten so the yield is higher, and far less insecticide has to be sprayed onto the field.
- 5
Explain why growing insect-resistant crops may harm other wildlife less than spraying insecticide does.
Model answer
The toxin only affects insects that actually eat the crop, whereas a spray drifts over a wide area and can kill harmless insects too.
- 6
Suggest why insect pests may in time become resistant to the toxin made by an engineered crop.
Model answer
The pests meet the toxin constantly, so any individual with a resistance mutation survives, breeds and passes the allele on until resistance is common.
Other ways to work this
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