Non-Communicable Disease and What Counts as a Risk Factor · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Risk factors are not guarantees

Science · The Human Body · ages 15-16
Name ______________________   Date ____________

  1. Which statement describes a benign tumour?

    • It does not invade nearby tissue or spread to distant sites.
    • It has not spread to distant sites, although it invades nearby tissue.
    • It is too small to cause symptoms, although its cells invade nearby tissue.

  2. Which statement defines a risk factor for a disease?

    • A feature known to cause the disease through a demonstrated biological pathway.
    • A feature linked to a higher chance of developing the disease.
    • A feature used to identify the disease once symptoms have already appeared.

  3. If a virus increases a person's cancer risk, the resulting cancer must also be passed from person to person.

    Circle one:   True   False

  4. A study finds more disease among people with a measured feature. No further causal evidence is supplied. Which conclusion is supported?

    • The feature contributes to causing disease by changing how cells function.
    • The feature is associated with disease; the cause of the link is unresolved.
    • The disease changes the feature, explaining why they occur together.

  5. Which statement describes a mechanism linking tobacco smoke to cancer?

    • People exposed to tobacco smoke have more lung cancer than people without that exposure.
    • Lung cancer rates fall in populations where smoking becomes less common over time.
    • Smoke chemicals damage DNA and can disrupt the controls on cell division.

  6. Which process produces new abnormal cells as a tumour grows?

    • Abnormal cells keep dividing after their division controls break down.
    • Existing abnormal cells enlarge as they absorb nutrients from the blood.
    • Existing abnormal cells move into spaces between nearby healthy cells.

  7. A tumour presses on an organ and has invaded nearby tissue. Tests find no distant spread. Which classification and reason fit?

    • A benign tumour, because pressure on an organ results from growth in one place.
    • A malignant tumour, because invasion of nearby tissue is malignant behaviour.
    • A benign tumour, because tests have not detected spread to a distant part of the body.

  8. A student says, 'Someone stopped smoking and later developed lung cancer, so stopping smoking cannot lower risk.' Which reply addresses the error?

    • The later diagnosis shows that inherited factors caused this person's cancer.
    • The later diagnosis shows that smoking was only a risk marker in this person's case.
    • A lower chance of lung cancer still allows some people who stop to develop it.
LightMySky · lightmysky.comW1-mt_IciZ1CJn6h-s1

Answer key

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

Risk factors are not guarantees W1-mt_IciZ1CJn6h-s1

  1. It does not invade nearby tissue or spread to distant sites. · Benign tumours do not invade or spread. Small size or a lack of distant spread does not make an invading tumour benign.
  2. A feature linked to a higher chance of developing the disease. · A risk factor is linked to increased disease risk. It need not have a demonstrated causal pathway and is not defined as a diagnostic sign.
  3. False · An infection can spread between people without the cancer it helps cause being transmissible.
  4. The feature is associated with disease; the cause of the link is unresolved. · The observation establishes an association. It does not establish either causal direction or a cellular mechanism.
  5. Smoke chemicals damage DNA and can disrupt the controls on cell division. · DNA damage followed by disruption of division controls describes how smoke can contribute to cancer. Population patterns describe associations rather than the biological pathway.
  6. Abnormal cells keep dividing after their division controls break down. · Cell division produces new cells. Enlargement changes cell size, while movement changes location; neither process by itself produces new cells.
  7. A malignant tumour, because invasion of nearby tissue is malignant behaviour. · Nearby tissue invasion identifies malignant behaviour. Pressure can occur with a benign tumour, and distant spread is not required for malignancy.
  8. A lower chance of lung cancer still allows some people who stop to develop it. · A later case is compatible with reduced risk. It does not identify that person's causes or show that smoking is only a marker.
Worksheet · LightMySky