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Exam questions · Biology · Variation and Evolution

Genetic Engineering

  • 8 exam questions
  • 25 marks
  • 8 quick checks
  1. 1 State [1 mark]

    What is meant by genetic engineering?

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    Model answer

    Modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic.

    Mark scheme

    • Introducing a gene from one organism into another to give a desired characteristic — 1 mark
  2. 2 Give [2 marks]

    Give two ways in which crop plants have been genetically engineered.

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    Model answer

    Any two of: to be resistant to diseases, to be resistant to insect attack, to be resistant to herbicides, to produce bigger or better fruits.

    Mark scheme

    • First correct way — 1 mark
    • Second correct way — 1 mark
  3. 3 Describe [2 marks]

    Describe how genetic engineering is used in the treatment of diabetes.

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    Model answer

    Bacterial cells are genetically engineered with the human insulin gene, so they make human insulin. The insulin is harvested and used to treat people with diabetes.

    Mark scheme

    • Bacteria are genetically engineered to make human insulin — 1 mark
    • The insulin is used to treat diabetes — 1 mark
  4. 4 Explain [4 marks]

    Some people are in favour of growing GM crops and some are against. Explain one reason in favour and one reason against.

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    Model answer

    In favour: GM crops generally show increased yields, which means more food can be produced from the same land, so more people can be fed. Against: there are concerns about the effects on populations of wild flowers and insects, and some people feel that the effects of eating GM crops on human health have not been fully explored.

    Mark scheme

    • In favour: increased yield or insect/herbicide resistance — 1 mark
    • Developed: more food or lower costs — 1 mark
    • Against: effect on wild flowers and insects or on health — 1 mark
    • Developed: for example populations may decline, or long-term effects are uncertain — 1 mark
  5. 5 Describe [4 marks]

    Describe the main steps in the process of genetic engineering of a bacterium to make human insulin.

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    Model answer

    Enzymes are used to isolate the human insulin gene from the DNA. The gene is inserted into a vector, which is usually a bacterial plasmid. The vector is used to insert the gene into the bacterial cells. The bacteria then divide and make human insulin.

    Mark scheme

    • Enzymes isolate the required gene — 1 mark
    • The gene is inserted into a vector such as a plasmid — 1 mark
    • The vector inserts the gene into the bacterial cells — 1 mark
    • The bacteria make the human insulin — 1 mark
  6. 6 Name [3 marks]

    The diagram shows the genetic engineering of bacteria. Name the substances that cut the gene out of the DNA, name the vector, and state what the bacteria make.

    Four steps in which a gene is cut out, put in a plasmid, put in a bacterium and the bacteria make insulin.
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    Model answer

    Enzymes cut the gene out. The vector is the plasmid. The bacteria make human insulin.

    Mark scheme

    • Enzymes — 1 mark
    • Plasmid — 1 mark
    • Human insulin — 1 mark
  7. 7 Explain [3 marks]

    Explain why genes are transferred to animals and plants at an early stage of their development when they are genetically engineered.

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    Model answer

    At an early stage the organism is only a few cells. If the gene is transferred then, every cell that develops from it will contain the gene. So the organism develops with the desired characteristic.

    Mark scheme

    • Early stage means few cells — 1 mark
    • All the cells that develop contain the gene — 1 mark
    • So the organism develops with the desired characteristic — 1 mark
  8. 8 Evaluate [6 marks]

    A company wants to grow a genetically modified crop that is resistant to insect attack. Evaluate the benefits and risks of growing the crop.

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    Model answer

    The crop is resistant to insects, so less is lost to pests and yields are higher. The farmer may need to use fewer insecticides, which saves money and may reduce pollution. However, there are concerns about the effects on populations of wild flowers and insects, because insects are part of food chains and pollinate flowers. Some people feel that the effects on human health of eating the crop have not been fully explored. Some people object to genetic engineering for ethical reasons. Overall, the benefits of food production may outweigh the risks if the crop is tested carefully, but some people will still object.

    Mark scheme

    • Higher yields because less is lost to insects — 1 mark
    • Fewer insecticides, so lower cost or less pollution — 1 mark
    • Effects on wild flowers and insects — 1 mark
    • Effects on human health not fully explored — 1 mark
    • Some people object on ethical grounds — 1 mark
    • A reasoned conclusion that weighs both sides — 1 mark

Quick check

  1. 1

    What does genetic engineering involve?

    1. ABreeding the best animals together
    2. BTaking cuttings from a plant
    3. CMoving a gene from one organism to another
    4. DGrowing cells in a dish
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    C: Moving a gene from one organism to another

    A gene is introduced from one organism into another to give a desired characteristic.

  2. 2

    Which substance is made by genetically engineered bacteria to treat diabetes?

    1. AHuman insulin
    2. BGlucagon
    3. CAdrenaline
    4. DAmylase
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    A: Human insulin

    Bacteria with the human insulin gene make human insulin.

  3. 3

    What are crops with modified genes called?

    1. AHybrid crops
    2. BCloned crops
    3. COrganic crops
    4. DGM crops
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    D: GM crops

    They are genetically modified (GM) crops.

  4. 4

    Which is a characteristic that GM crops may be given?

    1. AAbility to walk
    2. BResistance to insect attack
    3. CA loud call
    4. DFaster blood circulation
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    B: Resistance to insect attack

    Resistance to insect attack or herbicides is a common modification.

  5. 5

    Which is a concern about GM crops?

    1. AEffects on wild flowers and insects
    2. BThey produce too many seeds
    3. CThey are too heavy to harvest
    4. DThey cannot be eaten
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    A: Effects on wild flowers and insects

    There are concerns about effects on populations of wild flowers and insects.

  6. 6

    What are enzymes used for in genetic engineering?

    1. ATo make the vector grow
    2. BTo kill the bacteria
    3. CTo isolate the required gene
    4. DTo make the protein
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    C: To isolate the required gene

    Enzymes are used to isolate the required gene.

  7. 7

    Which of these is usually used as a vector?

    1. AA chloroplast
    2. BA ribosome
    3. CA red blood cell
    4. DA bacterial plasmid
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    D: A bacterial plasmid

    Vectors are usually bacterial plasmids or viruses.

  8. 8

    Why are genes transferred at an early stage of development?

    1. AThe organism is easier to cut
    2. BAll the cells that develop will contain the gene
    3. CThe gene cannot be added later
    4. DIt stops the organism growing
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    B: All the cells that develop will contain the gene

    Then all the cells that develop contain the gene, so the organism develops with the desired characteristic.