Worksheet: Human Defences Against Disease

In this worksheet, we will practice describing the physical and chemical defences of the human body.


Fill in the blanks: Pathogens are prevented from infecting our eyes by ; these contain , which break(s) down bacteria.

  • Atears, sulfuric acid
  • Bmucus, enzymes
  • Chairs, mucus
  • Dtears, lysozyme
  • Ecilia, enzymes


Which of the following describes how the stomach prevents pathogens from infecting humans?

  • AThe stomach produces antibiotics to break down and destroy any bacterial pathogens.
  • BThe stomach is lined with cilia that traps pathogens and moves them down the digestive system.
  • CThe stomach compresses after eating to squash and kill any pathogens.
  • DThe stomach contains acid that kills pathogens that have contaminated any food or drink a person consumes.
  • EThe stomach is lined with hairs that produce enzymes to break down pathogens.


Which of the following is an example of a physical defense against disease in humans?

  • AAntitoxins
  • BThe skin
  • CHydrochloric acid in the stomach
  • DAntifungals
  • ELysozyme in tears


Which of the following is an example of a chemical defense against disease in humans?

  • ACilia in the airways
  • BHydrochloric acid in the stomach
  • CCell walls
  • DA waxy cuticle
  • EThe skin


Which structure prevents pathogens from entering the human respiratory system by trapping dust and microorganisms in mucus?

  • ANasal hairs
  • BEyes
  • CAlveoli
  • DBronchioles
  • EThe stomach


Which of the following terms best describes defenses like skin, nasal hairs, and stomach acid?

  • ANonspecific
  • BSpecific


Is the presence of lysozyme in tears a chemical or a physical defense?

  • AChemical
  • BPhysical

Are nasal hairs a chemical or a physical defense?

  • APhysical
  • BChemical


The picture shows a scab forming over a recent wound.

Wound inflicted

What component of the blood helps the blood to clot?

  • AWhite blood cells
  • BEnzymes
  • CPlatelets
  • DPlasma
  • EHemoglobin


The given diagram shows cilia cells that line the trachea and other airways in the lungs. Which of the following best describes how cilia defend humans from disease?

  • ACilia contain enzymes that break down the cell wall of pathogens.
  • BCilia release hydrochloric acid that destroys the pathogens.
  • CCilia trap pathogens in mucus and move them to the throat, then to the stomach to be destroyed.
  • DCilia produce mucus that contains antibiotics that destroy bacterial cells.
  • ECilia engulf the pathogens and destroy them through digestion.

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.