Pathogens Cause Disease

Question 1

What is a pathogen?

Answer 1

Pathogens are microorganisms which cause disease.

Question 2

How do pathogens cause disease?

Answer 2

1. Viruses damage host cells by entering, reproducing and leaving (cells burst).
2. Bacteria produce and release toxins which damage host cells.

Question 3

State the different ways pathogens can be transmitted

Answer 3

1. Contaminated food/water
2. Air borne
3. Sexual intercourse
4. Blood to blood contact
5. Mother to foetus

Question 4

What is an antigen?

Answer 4

Antigens are molecules that cause an immune response.

Question 5

Where can an antigen be found?

Answer 5

• in the cell membrane of pathogens
• on the surface of viruses
• as free molecules, such as toxins
• on the cell surface of a tissue or organ transplant
• in the cell membrane of cancer cells