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Exam questions · Biology · DNA and Protein Synthesis

The Genome and the Human Genome Project

  • 6 exam questions
  • 19 marks
  • 9 quick checks
  1. 1 State [1 mark]

    State what is meant by the genome of an organism.

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    Model answer

    The entire DNA of an organism.

    Mark scheme

    • All of an organism's DNA — 1 mark
  2. 2 State [2 marks]

    State two things that the Human Genome Project found.

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    Model answer

    Any two from: the order of all of the bases in human DNA; that humans have about 20 000 genes; the positions of many genes; that people are more than 99% identical in their DNA.

    Mark scheme

    • First finding — 1 mark
    • Second finding — 1 mark
  3. 3 Describe [3 marks]

    Describe how the Human Genome Project was used to find the order of bases in human DNA.

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    Model answer

    DNA from volunteers was broken into small pieces. The order of bases in each piece was read by sequencing machines. Computers then put the overlapping pieces together to give the full sequence.

    Mark scheme

    • DNA broken into small pieces — 1 mark
    • Sequence of each piece read by machines — 1 mark
    • Computers assembled the full sequence — 1 mark
  4. 4 Explain [3 marks]

    Explain how a genetic test could help a person who has several relatives with breast cancer.

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    Model answer

    The test can show whether she has a variant of a gene, such as BRCA1, that increases the risk of cancer. If she has the variant, she can have regular screening, so that any cancer is found early and treated more successfully. She could also decide to take other preventive steps.

    Mark scheme

    • Test for a gene variant such as BRCA1 — 1 mark
    • Shows a higher risk — 1 mark
    • Early screening or prevention — 1 mark
  5. 5 Explain [4 marks]

    Explain two ways in which knowing the genome helps doctors to treat patients.

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    Model answer

    Doctors can use genetic tests to find the variants that make a person more likely to develop a disease, so they can give early screening or lifestyle advice. They can also choose the best drug and dose using the person's genes, so that the treatment works well and has fewer side effects.

    Mark scheme

    • Predict risk of disease — 1 mark
    • Developed: screening, lifestyle advice — 1 mark
    • Personalised medicine — 1 mark
    • Developed: best drug and dose — 1 mark
  6. 6 Discuss [6 marks]

    Discuss the potential benefits and problems of using information from the Human Genome Project in medicine.

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    Model answer

    Knowing the genome lets doctors find the genes that cause inherited disorders, test people for variants that raise their risk of disease and choose treatments that suit a person's genes. This could lead to earlier diagnosis and better treatment, and it helps researchers to develop new drugs and gene therapies. There are also problems. Genetic information is private, and insurers or employers might use it to discriminate against people. People could become very anxious if they are told they are likely to develop a disease for which there is no cure. Testing is also expensive, so not everyone may benefit. Overall the benefits are large if the information is kept private and properly regulated.

    Mark scheme

    • Finds genes for disorders / predicts risk — 1 mark
    • Personalised treatment or new drugs — 1 mark
    • Developed example — 1 mark
    • Privacy or discrimination — 1 mark
    • Anxiety or cost — 1 mark
    • A reasoned conclusion — 1 mark

Quick check

  1. 1

    Roughly how many genes are in the human genome?

    1. A2000
    2. B20 000
    3. C200 000
    4. D2 million
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    B: 20 000

    The Human Genome Project found about 20 000 genes.

  2. 2

    What was the aim of the Human Genome Project?

    1. ATo find the order of all of the bases in human DNA
    2. BTo clone a human
    3. CTo make a new species
    4. DTo count all of the people in the world
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    A: To find the order of all of the bases in human DNA

    The project aimed to find the order of all of the bases in human DNA.

  3. 3

    What is a genome?

    1. AA single gene
    2. BA chromosome
    3. CAll of an organism's DNA
    4. DA protein
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    C: All of an organism's DNA

    The genome is all of the DNA of an organism.

  4. 4

    Which statement about the DNA of two people is correct?

    1. AIt is about 50% identical
    2. BIt is completely different
    3. CIt is completely identical
    4. DIt is more than 99% identical
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    D: It is more than 99% identical

    Any two people have DNA that is more than 99% identical.

  5. 5

    Which is a benefit of the Human Genome Project?

    1. AIt helps to identify genes that cause inherited disorders
    2. BIt cures all diseases
    3. CIt stops people from being born with variants
    4. DIt removes the need for medicines
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    A: It helps to identify genes that cause inherited disorders

    Knowing the genes helps scientists find which genes cause disorders, and so predict and treat them.

  6. 6

    What is personalised medicine?

    1. AMedicine made at home
    2. BTreatment chosen using the patient's own genes
    3. CMedicine without side effects
    4. DA drug that everyone takes
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    B: Treatment chosen using the patient's own genes

    Personalised medicine uses information from a patient's genes to choose the most suitable treatment.

  7. 7

    Which is a possible problem of genetic testing?

    1. AIt makes people less healthy
    2. BIt changes the person's DNA
    3. CDiscrimination by insurers or employers
    4. DIt is always inaccurate
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    C: Discrimination by insurers or employers

    Insurers or employers could use genetic information to discriminate against people.

  8. 8

    Roughly how many base pairs are in the human genome?

    1. A3 thousand
    2. B3 million
    3. C30 million
    4. D3 billion
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    D: 3 billion

    There are about 3 billion base pairs.

  9. 9

    Only a small part of the human genome is made up of genes. What is the rest called?

    1. AMutant DNA
    2. BNon-coding DNA
    3. CCytoplasm
    4. DRNA
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    B: Non-coding DNA

    DNA that does not code for a protein is non-coding DNA, and some of it controls when genes are used.