12.5 Non Specific Animal Defences Against Pathogens

Question 1

Non specific animal defences

Answer 1

Skin
Mucous membranes
Lysozymes

Question 2

How is the skin a defence against pathogens?

Answer 2

Prevents entry of pathogens
Skin flora of good bacteria outcompete the pathogens
Produces sebum - oily substance that inhibits the growth of pathogens

Question 3

Why are mucous membranes good for defence against pathogens?

Answer 3

Secrete sticky mucus - traps microorganisms
Contain lysozymes - destroys bacterial and fungal cell walls
Mucus contains phagocytes - remove remaining pathogens

Question 4

Lysozymes

Answer 4

Found in tears. urine and stomach acid
Prevent pathogens getting into our body

Question 5

Expulsive reflexes

Answer 5

Coughs and sneezes eject mucus containing pathogens from the gas exchange system
Vomiting/diarrhoea expel contents of the gut along with infective pathogens