topic 11 - Animal Physiology

Question 1

What are antigens?

Answer 1

All organisms have unique molecules on the surface of cells

Molecules that trigger immune responses

Question 2

Antigens act to trigger the production of specific antibodies. Provide an example.

Answer 2

Antigens on red blood cells will stimulate antibody production in a person with a different blood group

Question 3

Antibodies aid in pathogen destruction by promoting…

Answer 3

Think: PANIC

• Phagocyte recruitment
• Agglutination
• Neutralization
• Inflammation
• Complement activation

Question 4

There are two types of immunity. What are they?

Answer 4

Immunity can be active (able to produce own antibodies)

Immunity can be passive (acquires antibodies externally)

Question 5

Immunity can be active (able to produce own antibodies). What is it’s two sub types?

Answer 5

• Natural active immunity = normal response to infection

* Artificial active immunity = immunity via vaccination

Question 6

Immunity can be passive (acquires antibodies externally). What is it’s two sub types?

Answer 6

• Natural passive immunity = via breastfeeding

* Artificial passive immunity = monoclonal antibodies

Question 7

Describe clonal selection.

Answer 7

Immune systems must be challenged with specific antigens in order to initiate an appropriate response (antibody production)
• MacrophagespresentantigenfragmentstoTHcells
• TH cells activate antigen-specific B cells (clonal selection)
• The B cells divide and differentiate into plasma cells that
produce large quantities of specific antibodies
• A small proportion differentiate into B memory cells

Question 8

The adaptive immune response includes the production of memory cells following an initial pathogenic infection. How does memory cells work?

Answer 8

• memory cells persist for years. secreting antibodies
• if re-infection with the same antigen occurs, memory cells can respond faster and with much greater potency
• as a result, disease symptoms do not develop (immunity)

Question 9

What are vaccines? How do they work? Provide an example.

Answer 9

Vaccines contain attenuated forms of a pathogen (cannot cause the disease, but can stimulate an immune response)
Vaccines induce active immunity by stimulating the presence of memory cells (confers long-term immunity)
When exposed to the actual pathogen, the memory cells will trigger a significantly faster and stronger immune response
• Periodic booster shots may still be required
Smallpox was the first disease eradicated by vaccination

Question 10

What are monoclonal antibodies?

Answer 10

Monoclonal antibodies are antibodies that have been derived from a single B cell clone (i.e. identical specific antibodies)

Monoclonal antibodies for hCG are used to test pregnancy
• Results detected via enzyme-linked immunosorbant assay

Question 11

Monoclonal antibodies are antibodies that have been derived from a single B cell clone (i.e. identical specific antibodies). Provide an example.

Answer 11

• An animal (e.g. mouse) is injected with a pathogen to
stimulate production of specific plasma cells
• The plasma cells are removed and fused with tumor cells
capable of endless divisions
• The hybridoma formed will mass-produce the antibody