1. 1
   A team of scientists is genetically modifying a crop plant by inserting a gene from a soil bacterium that gives resistance to a common insect pest. This involves removing, changing or inserting individual genes into the plant's genetic material.

   (a)

   Scientists want to insert a gene from one organism into a completely different, unrelated organism to give it a new characteristic. What is this overall process called?

   [1 mark]

   • AGenetic modification
   • BSelective breeding
   • CNatural selection
   • DMeiosis

   (b)

   Which of the following best defines genetic modification?

   [1 mark]

   • AAllowing organisms to breed randomly without human intervention
   • BChanging the genetic material of an organism by removing, changing or inserting individual genes
   • CMeasuring the size of an organism using a microscope
   • DClassifying organisms into kingdoms based on shared features

   (c)

   Explain why scientists might choose to genetically modify a crop plant to be resistant to an insect pest, rather than relying on traditional selective breeding to achieve this outcome.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   Scientists isolate a gene from a donor organism's DNA using a restriction enzyme, which produces sticky ends at the cut site. The same restriction enzyme is then used to cut a bacterial plasmid, which will act as a vector to carry the gene into a new host organism.

   (a)

   To begin the genetic modification process, scientists need to isolate a specific gene from a donor organism's DNA. Which type of enzyme is used to cut out this gene, producing sticky ends?

   [1 mark]

   • ARestriction enzyme
   • BDNA ligase
   • CAmylase
   • DProtease

   (b)

   The same restriction enzyme used to isolate the gene is then used to cut open a bacterial plasmid, which will act as a vector. Why is it important to use the same restriction enzyme on both the gene and the plasmid?

   [1 mark]

   • ASo that the plasmid is completely destroyed
   • BSo that both pieces of DNA have complementary sticky ends that can join together
   • CSo that the gene is converted into a protein immediately
   • DSo that the plasmid can no longer replicate

   (c)

   Describe how the isolated gene and the cut plasmid are joined together, and explain what the resulting structure is called.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A biotechnology laboratory has produced a recombinant plasmid containing a human insulin gene and needs to insert it into bacteria, then identify which bacteria have taken up the plasmid successfully, before allowing these modified bacteria to multiply and express the human gene to produce insulin on a large scale.

   (a)

   After a recombinant plasmid containing a human insulin gene has been produced, describe how it is inserted into bacteria, and explain how scientists can identify and select the bacteria that have successfully taken up the recombinant plasmid.

   [3 marks]

   (b)

   Once bacteria containing the recombinant plasmid have been identified and selected, describe the remaining steps needed to produce insulin on a large scale, and explain what is meant by gene expression in this context.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   An advanced biology class is studying the complete genetic modification process used to produce a human protein in bacteria, and comparing it with a proposed process to genetically modify a crop plant to make it resistant to a herbicide, so that the herbicide can be used to kill weeds without harming the crop.

   (a)

   Explain fully, in the correct order, the entire process of genetically modifying bacteria to produce a human protein, from isolating the human gene through to large-scale production of the protein, naming the enzymes involved at each stage and describing the purpose of each stage.

   [6 marks]

   (b)

   Scientists are also developing a genetically modified crop plant that is resistant to a particular herbicide, by inserting a herbicide-resistance gene from a bacterium into the plant's cells. Explain how this process would be similar to, and different from, the process used to genetically modify bacteria to produce a human protein, and explain one potential benefit and one potential concern of using this herbicide-resistant genetically modified crop.

   [6 marks]

   Total for question 4: 12 marks

End of questions