infection & response

Question 1

What are the 4 types of pathogen? GIve an example of each.

Answer 1

Bacteria - Salmonella
Fungi - Rosa Black Spot
Protists - Malaria
Virus - TMV

Question 2

What causes gonorrhoea?
What causes HIV?

Answer 2

• Bacteria
• Virus

Question 3

Describe how viruses cause disease.

Answer 3

A virus reproduces rapidly inside cells and produces toxins, causing inflammation. Usually the cell will burst, releasing the virus.

Question 4

Define ‘protist’

Answer 4

A single-celled eukaryote that causes disease.

Question 5

Give four ways to reduce the spread of disease.

Answer 5

• Good hygiene
• Destroying vectors
• Vaccination
• Isolating infected individuals

Question 6

How do you convert from centimeters to micrometers?

Answer 6

Multiply by 10,000

Question 7

How is the human body adapted to defend against disease?
(3)

Answer 7

• Skin acts as a barrier
• Mucus in the trachea & bronchi trap pathogens, which are wafted up to be swallowed by cilia cells.
• Stomach acid

Question 8

Name 3 ways white blood cells attack invading microbes.

Answer 8

• Phagocytosis
• Producing antibodies to lock onto invading cells so they can be found & destroyed
• Producing antitoxins to counteract toxins produced

Question 9

How does vaccination work?

Answer 9

A small amount of dead or inactive pathogen is introduced to the body, triggering an immune response - white blood cells (lymphocytes) produce antibodies complementary to the pathogen’s antigens. If the same pathogen is encountered again, antibodies can be produced much quicker, preventing disease. This is the secondary immune response.

Question 10

Which plants do aspirin and digitalis come from?

Answer 10

Willow and foxglove

Question 11

What are the three main stages of drug trials?
What do drug trials aim to find out?

Answer 11

Preclinical (tissues)
Preclinical (animals)
Clinical (healthy humans)

Efficacy, toxicity, and dosage.

Question 12

Are viruses alive? Why or why not?

Answer 12

No: they cannot reproduce independently, they require other cell’s ‘machinery’ to replicate themselves.

Question 13

Describe how bacteria cause disease.

Answer 13

Bacteria reproduce rapidly inside the body, and produce toxins which damage cells and tissues.

Question 14

What is a vector?

Answer 14

A vector is a carrier of disease that does not get the disease itself

Question 15

What is phagocytosis?

Answer 15

White blood cells find pathogens, bind to them and engulf them, allowing the pathogen to be destroyed.