5.7 Human defence responses

Question 1

Describe why washing your hands when preparing a salad can help prevent the spread of disease?

Answer 1

prevents pathogens transferring from hands to food

Question 2

Describe why throwing away tissues after you’ve blown your nose can help prevent the spread of disease?

Answer 2

prevents pathogens coming into contact with other people or your hands

Question 3

Describe why making sure that sewage does not get into drinking water can help prevent the spread of disease?

Answer 3

prevents pathogens from gut being taken in with drinking water

Question 4

Why does your blood not clotting properly increase your risk of getting infections.

Answer 4

Clotted blood prevents pathogens getting into body through cuts in skin.
If blood won’t clot properly, pathogens may get in through open cuts

Question 5

Why does the number of white cells in your blood falling, increase your risk of getting infections.

Answer 5

White blood cells destroy pathogens.

If number of white blood cells falls, fewer pathogens will be destroyed, increasing likelihood of infection

Question 6

Discuss how your white blood cells help to prevent you from suffering from communicable diseases.

Answer 6

• to include detail on ingestion and digestion (destruction) of microorganisms,
• production of antibodies to target and destroy particular pathogens,
• production of antitoxins to counteract toxins released by pathogens