Cancer & Stem Cells · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.
به انگلیسی

Cancer & Stem Cells

Science · The Human Body · ages 13-14
Name ______________________   Date ____________

  1. Which sentence best describes a stem cell?

    • A cell that already has one fixed job, like a nerve cell
    • An unspecialised cell that can still form other types
    • A cell found only in plants, never in animals

  2. What actually causes a cell to become cancerous?

    • A mutation breaks cell division control genes
    • The cell catches a cold virus that never goes away
    • The cell simply gets too old to work properly

  3. Scientists and the public all agree that using embryonic stem cells for research is entirely acceptable.

    Circle one:   True   False

  4. A doctor wants to grow new heart muscle cells for a patient with damaged tissue. Why start with stem cells instead of already-specialised cells?

    • Stem cells can still form the needed cell type
    • Specialised cells divide faster than stem cells do
    • Specialised cells are easier to keep alive in a lab dish

  5. Look at the sequence. Which step shows the cell's stop signal failing?

    Normal cellMutationBrakes offTumour
    • Normal cell
    • Tumour
    • Brakes off

  6. Which of these is a genuine scientific argument in favour of embryonic stem cell research?

    • These stem cells are sold cheaply at any pharmacy
    • These stem cells can become almost any tissue type, giving them wide medical potential
    • These stem cells require no laboratory equipment to grow

  7. Which of these is an ethical objection to embryonic stem cell research, rather than a scientific one?

    • Removing the stem cells destroys an embryo that some believe deserves protection
    • The stem cells can develop into almost any tissue type
    • The stem cells can be grown and studied in a laboratory

  8. A student claims: 'One single mutation always causes cancer right away.' What is wrong with this claim?

    • Mutations can only happen in a person's first year of life
    • Cancer only forms in cells that never divide at all
    • Cancer usually needs several mutations to build up over time before enough controls fail
LightMySky · lightmysky.comW1-mt_roinupb_7L-s1

Answer key

For grown-ups. Fold this page away before handing over the rest.

Cancer & Stem Cells W1-mt_roinupb_7L-s1

  1. An unspecialised cell that can still form other types · A stem cell has not committed to one job yet, so it can develop into several different specialised cells.
  2. A mutation breaks cell division control genes · Cancer starts inside the cell's own DNA. A mutation disables the genes that normally control when a cell divides.
  3. False · This is a genuine, ongoing debate. Some people focus on the medical benefits, others on the ethical cost of destroying an embryo.
  4. Stem cells can still form the needed cell type · Stem cells have not chosen a job yet, so scientists can guide them into becoming the specific tissue a patient needs.
  5. Brakes off · That is the step where checkpoint genes stop working, so the cell can keep dividing without permission.
  6. These stem cells can become almost any tissue type, giving them wide medical potential · Embryonic stem cells are especially flexible, which is the main scientific reason researchers value them.
  7. Removing the stem cells destroys an embryo that some believe deserves protection · This concern is about moral status and protection, not about how the cells behave biologically.
  8. Cancer usually needs several mutations to build up over time before enough controls fail · Most cancers develop gradually, as damage builds up across several genes that control division, not from one instant change.
Worksheet · LightMySky