5.1 Defence mechanisms

Question 1

What is pathogen?

Answer 1

Any microorganisms that cause diseases.

Question 2

What is immunity?

Answer 2

The body protects itself from infection.

Question 3

Which 2 groups can defence mechanism be grouped into?

Answer 3

1. specific
2. non-specific

Question 4

What is specific defence mechanism?

Answer 4

Responses that are slower and specific to each pathogen.

Question 5

What are the examples of specific defence mechanism?

Answer 5

1. cell-mediated responses (eg. T lymphocytes)
2. humoral responses (eg. B lymphocytes)

Question 6

What is non-specific defence mechanism?

Answer 6

Responses that are immediate and the same for all pathogens.

Question 7

What are the examples of non-specific defence mechanism?

Answer 7

1. physical barrier (eg. skin)
2. phagocytosis

Question 8

What is on every cell’s surface that identify it?

Answer 8

Antigen

Question 9

What is antigen?

Answer 9

A molecule that triggers an immune response by lymphocytes.

Question 10

What does antigen contain and what does it do?

Answer 10

Proteins

Question 11

What does the protein in antigens do?

Answer 11

Enables the immune system to identify:
1. pathogens
2. cells from other organisms of the same species/non-self material
3. abnormal body cells
4. toxins

Question 12

Although the identification of pathogens, non-self material, abnormal body cells and toxins are good, which type of humans is this bad for? Why?

Answer 12

Humans who have organ or tissue transplant, because the immune system will recognise the new organ or tissue as non-self.

Question 13

What are lymphocytes?

Answer 13

Types of white blood cells that are responsible for the immune response. They become activated in the presence of antigens.

Question 14

What are the 2 types of lymphocytes?

Answer 14

1. B lymphocytes
2. T lymphocytes