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Exam questions · Biology · Culturing Microorganisms and Developing Medicines

Making Monoclonal Antibodies

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

    State what is meant by a monoclonal antibody.

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    Model answer

    An antibody produced by a clone of identical cells, all of which fit the same antigen.

    Mark scheme

    • Identical antibodies from a clone of cells — 1 mark
  2. 2 State [2 marks]

    Name the two types of cell that are joined together to make a hybridoma cell, and state one useful property that each gives to the hybridoma cell.

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    Model answer

    A lymphocyte, which makes the desired antibody, and a tumour cell, which divides quickly.

    Mark scheme

    • Lymphocyte, makes the antibody — 1 mark
    • Tumour cell, divides rapidly — 1 mark
  3. 3 Explain [3 marks]

    Explain why a mouse is injected with an antigen when monoclonal antibodies are made.

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    Model answer

    The antigen stimulates the mouse's lymphocytes to make antibodies that fit it. These lymphocytes can then be collected, and are used to make the hybridoma cells that make this particular antibody.

    Mark scheme

    • Antigen makes lymphocytes produce antibodies — 1 mark
    • The antibodies fit that antigen — 1 mark
    • The lymphocytes are collected to make hybridomas — 1 mark
  4. 4 Describe [4 marks]

    Describe how monoclonal antibodies are made, from the injection of the mouse to the collection of the antibody.

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    Model answer

    A mouse is injected with an antigen. The lymphocytes that make the antibody are removed and joined with tumour cells to make hybridoma cells. The hybridoma cells that make the right antibody are selected, and grown in large numbers by cell division, and the antibody is collected and purified.

    Mark scheme

    • Mouse injected with antigen — 1 mark
    • Lymphocytes fused with tumour cells — 1 mark
    • Selected hybridomas grown in large numbers — 1 mark
    • Antibody collected — 1 mark
  5. 5 Calculate [3 marks]

    A hybridoma cell divides once every 12 hours. Calculate the number of cells after 3 days, starting with one cell.

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    Model answer

    3 days is 72 hours, so there are 72 ÷ 12 = 6 divisions. 2 to the power 6 is 64 cells.

    Mark scheme

    • 6 divisions — 1 mark
    • 2 to the power 6 — 1 mark
    • 64 cells — 1 mark
  6. 6 Explain [6 marks]

    Explain why neither a lymphocyte nor a tumour cell can be used alone to make large amounts of a monoclonal antibody, and why hybridoma cells can.

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    Model answer

    A lymphocyte that makes the right antibody can produce it, but it does not divide in a laboratory, so only a very small number of cells, and little antibody, could be obtained. A tumour cell divides rapidly, but does not make the antibody that is needed, so it would produce none. A hybridoma cell is formed by fusing the two. It has the genes from the lymphocyte to make the specific antibody, and the property from the tumour cell of dividing continuously. It can therefore be grown in large numbers, as a clone, and every cell makes the same antibody, so a large supply can be collected.

    Mark scheme

    • Lymphocyte makes the antibody — 1 mark
    • But does not divide — 1 mark
    • Tumour cell divides — 1 mark
    • But does not make the right antibody — 1 mark
    • Hybridoma has both features — 1 mark
    • Cloned in large numbers to make identical antibodies — 1 mark

Quick check

  1. 1

    What does a hybridoma cell do?

    1. AOnly makes antibodies
    2. BMakes antibodies and divides
    3. COnly divides
    4. DDigests pathogens
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    B: Makes antibodies and divides

    It makes the desired antibody and it divides.

  2. 2

    Which cell gives a hybridoma the ability to divide?

    1. AA red blood cell
    2. BA nerve cell
    3. CA tumour cell
    4. DA lymphocyte
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    C: A tumour cell

    Tumour cells divide rapidly and for a long time.

  3. 3

    Why is the mouse injected with an antigen?

    1. ASo that it makes the desired lymphocytes
    2. BTo kill it
    3. CTo make tumour cells
    4. DTo make it grow
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    A: So that it makes the desired lymphocytes

    So that its lymphocytes make antibodies against the antigen.

  4. 4

    What does the word monoclonal mean?

    1. AMany different antibodies
    2. BAntibodies from many animals
    3. CAntibodies against many antigens
    4. DIdentical antibodies from a clone of cells
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    D: Identical antibodies from a clone of cells

    The antibodies all come from one clone, so they are identical.

  5. 5

    Why can an ordinary lymphocyte not be used to make a large amount of antibody?

    1. AIt makes the wrong antibody
    2. BIt is too big
    3. CIt does not divide in a laboratory
    4. DIt kills the mouse
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    C: It does not divide in a laboratory

    It does not divide outside the body.

  6. 6

    A hybridoma cell divides once every day. How many cells will there be after 5 days from one cell?

    1. A10
    2. B32
    3. C25
    4. D5
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    B: 32

    \(2^5 = 32\).

  7. 7

    How are hybridoma cells made?

    1. ABy fusing a lymphocyte with a tumour cell
    2. BBy injecting a mouse with a drug
    3. CBy mixing two antibodies
    4. DBy heating a lymphocyte
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    A: By fusing a lymphocyte with a tumour cell

    By fusing a lymphocyte with a tumour cell.

  8. 8

    What is done with the antibodies at the end of the process?

    1. AThey are destroyed
    2. BThey are injected back into the mouse
    3. CThey are fused with bacteria
    4. DThey are collected and purified
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    D: They are collected and purified

    They are collected and purified.

  9. 9

    Why do all of the antibodies from one hybridoma culture have the same shape?

    1. AThey are all made by different cells
    2. BAll of the cells are clones with the same genes
    3. CThe antigen changes them
    4. DThey are made in a fermenter
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    B: All of the cells are clones with the same genes

    The cells are a clone, so they have identical genes, and make identical proteins.