Question 1
Define the term genetic modification.
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- changing the genetic material of an organism (1)
- by removing, changing or inserting individual genes (1)
Question 2
Which is an example of genetic modification?
- Crossing two different varieties of wheat
- Inserting a human gene into bacteria so they make insulin
- Treating diabetes with insulin injections
- Growing yeast in a fermenter
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Answer: B (1)
Question 3
Outline three ways in which genes have been inserted into crop plants to improve them.
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- gene for resistance to herbicides (1)
- gene for resistance to insect pests (1)
- gene to improve nutritional quality (1) allow golden rice / more vitamin A
Question 4
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanBacteria can be genetically modified to make human insulin. Outline the process, starting from the human insulin gene.
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- gene cut out of human DNA using restriction enzymes (1)
- leaving sticky ends (1)
- plasmid cut with the same restriction enzyme, giving complementary sticky ends (1)
- gene joined into plasmid using DNA ligase, forming a recombinant plasmid (1) reject ligase cuts
- recombinant plasmid inserted into bacteria (1)
- bacteria multiply (1)
- bacteria express the gene / make insulin (1)
- Max 5
Question 5
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanWhich enzyme is used to join a human gene into a bacterial plasmid?
- Restriction enzyme
- DNA ligase
- Amylase
- Protease
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Answer: B (1)
Question 6
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanMaize can be genetically modified to be resistant to insect pests. Discuss the advantages and disadvantages of growing this GM maize.
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- advantage: higher yield as fewer plants are damaged by insects (1)
- advantage: less insecticide needed, saving money / less harm to other insects (1)
- disadvantage: gene could spread to wild plants (1)
- disadvantage: may harm non-pest insects / reduce biodiversity (1)
- disadvantage: insect pests may become resistant (1)
- disadvantage: seeds expensive / long-term effects on health not known (1)
- Max 4; Max 3 if only advantages or only disadvantages