Chapter 5 - Practice Questions

Question 1

What type of pathogen causes AIDS?

Answer 1

virus

Question 2

What type of pathogen causes malaria?

Answer 2

protist

Question 3

What type of pathogen causes salmonella food poisoning?

Answer 3

bacterium

Question 4

Rose black spot is a fungal infection of roses. Black spots appear on the leaves. The leaves may turn yellow and drop from the plant.

Explain how rose black spot disease might affect the growth of a rose bush?

Answer 4

less chlorophyll / leaves (so) less light absorbed
or
-less photosynthesis (so) less sugar / glucose / food
made

Question 5

Suggest two things a gardener could do to kill the fungus and reduce the chance of another rose black spot infection?

Answer 5

• use a fungicide

- remove and destroy / burn the infected leaves

Question 6

Pathogens can enter the body through cuts in the skin, through the breathing system, and through the digestive system.

Describe how the body is adapted to reduce the entry of pathogens through these three routes?
6 Marks

Answer 6

ANY SIX FROM
skin defences:
 microorganisms cover skin and act as barrier
against pathogens
 platelets in blood form clot that dries into scab,
stopping pathogens getting in
 skin produces antimicrobial secretions which destroy
pathogenic bacteria

respiratory defences:
 nose has hairs and produces mucus which traps pathogens from air
 trachea and bronchi also secrete mucus
 cilia waft mucus towards throat to be swallowed

digestive defences:
 stomach produces acid which destroys microorganisms

Question 7

Describe two ways that white blood cells can kill pathogens

Answer 7

by phagocytosis

by producing antibodies

Question 8

If pathogens reproduce to form a large population inside the body they cause an infection. The person may feel ill.
Describe how white blood cells can reduce the symptoms of an infection

Answer 8

produce antitoxins