The Immune System

Question 1

How are T-lymphocytes activated?

Answer 1

By antigens presented on phagocytes

Question 2

What are the two types of T-lymphocyte?

Answer 2

• T-helper cells

- Cytotoxic T-cells

Question 3

What do T-helper cells do?

Answer 3

Activate B-cells and cytotoxic T-cells

Question 4

What do cytotoxic T-cells do?

Answer 4

Kill pathogens (cellular response)

Question 5

What are antibodies?

Answer 5

Proteins that bind to antigens to kill pathogens

Question 6

What do B-cells do?

Answer 6

Undergo clonal selection

Question 7

What is clonal selection?

Answer 7

The B-cell with the complimentary antibody to the pathogens antigen (and can therefore form an antigen-antibody complex) is selected and divides into many copies called plasma cells

Question 8

What are plasma cells?

Answer 8

Clones of the selected B-cell with the complimentary antibody to the pathogens antigen

Question 9

What do plasma cells do?

Answer 9

• Make monoclonal antibodies (that can form an antibody-antigen complex with pathogens antigen)
• Monoclonal antibodies can then stick pathogens together (agglutination) so phagocytes can engulf many pathogens at once

Question 10

What happens to plasma cells post infection?

Answer 10

Some plasma cells are saved as memory B-cells which are reactivated If there is a secondary response