6.3.5 - Developing immunity

Question 1

Explain what a graph looks like where the concentration of antibodies in the blood is measured over a primary and secondary response to an antigen.

Answer 1

The concentration increases after first exposure as B cells divide by mitosis and produce antibodies.
Then the level drops, but not to 0 as memory lymphocytes remain.
Second increase is much more rapid and goes to a higher level.

Question 2

Why was the plasma of some men who survived COVID-19 donated?

Answer 2

It contained antibodies against the virus.

Question 3

What is passive immunity?

Answer 3

Passive immunity is when antibodies are introduced from outside the body, you do not have to make them yourself.

Question 4

List and advantage and a disadvantage of using passive immunity?

Answer 4

adv: immediate source of antibodies

dis: short term solution, person will not have long-lasting protection

Question 5

what is an example of natural passive immunity?

Answer 5

When an infant receives antibodies from mothers breast milk

Question 6

What is active immunity?

Answer 6

The development of antibodies after exposure to a pathogen or antigen.

Either through infection or vaccination

Question 7

What is the aim of a vaccination?

Answer 7

Vaccination aims to stimulate a primary immune response, without actually causing the disease like a normal infection would.

Question 8

Explain why there is a delay between the first infection by the pathogen and the appearance of antibodies in the blood. [2 marks]

Answer 8

The B cells need to match with complementary antigens.
Then divide by mitosis when activated.
This then produces plasma cells and releases antibodies.