Lesson 9 Acquiring Immunity

Question 1

What is passive immunity?

natural/artfiicial

Answer 1

Passive immunity is when a person receives antibodies from another source
Natural: Placental transfer, Breast milk
Artificial: Injection of antivenom

Question 2

Active immunity

Answer 2

Active immunity is when an individual resonds to antigen and makes their own antiodies
Natural: Infection of pathogen
Artificial: Vaccination

Question 3

What is a Vaccine?

Answer 3

A vaccine is a solution containing dead, weakened or attenuated form of the pathogen or antigen.

Question 4

What do Antiviral drugs do?

Answer 4

Prevent viruses binding to receptors that allow them to enter cells
Inhibit viral enzymes involved in viral replication
Block transcription and translation of viral proteins
Prevent viruses from leaving host cells

Question 5

Describe how a vaccine provides immunity

Answer 5

Vaccine containing antigen circulates in the body
non-self antigens are recognised by T helper cells and B cells
T helper cells activate B cells to divide by mitosis
These divide to produce plasma cells which will produce specific free floating antibodies AS WELL AS
B memory cells which remain in circulation
B memory cells rapidly produce a higher concentration of antibodies if infection reoccurs

Question 6

Describe the role of a B cell plays in an adaptive immune response

Answer 6

• B cells form part of the adaptive immune system
• Once activated by a T cell, a B cell divides by mitosis
• Producing B memory cells and Plasma cells
• Plasma cells produce specific and free-floating antibodies (proteins)
• B memory cells remain in circulation in case of a secondary infection of a pathogen