5.4- B LYMPHOCTES AND HUMORAL IMMUNITY

Question 1

What is the first phase of the specific response to infection?

Answer 1

mitotic division of specific T cells to form a clone of the relevant T cells produce factors to stimulate B cells to divide

Question 2

What are the B cells involved in? (hint-phase)

Answer 2

next phase of immune response- humoral immunity

Question 3

Why is humoral immunity so called?

Answer 3

as it involves antibodies

Question 4

Where are are antibodies soluble in?

Answer 4

blood + tissue fluid of body

Question 5

What is an old-fashioned word for body fluid?

Answer 5

‘humour’

Question 6

How many different types of B cells are there?

Answer 6

may different types

Question 7

What does each B cell produce?

Answer 7

specific antibody that responds to one specific antigen

Question 8

Examples of antigens? (5)

Answer 8

protein on surface of pathogen
foreign cell
toxin
damaged/ abnormal cell

Question 9

What happens when an antigen enters the blood or tissue fluid?

Answer 9

there will be a B cell that has an antibody on its surface whose shape exactly fits antigen, they’re complementary
antibody attaches to complementary antigen

Question 10

Through what process does the antigen enter the B cell?

Answer 10

endocyotsis

Question 11

What happens to the antigen after it has entered the B cell?

Answer 11

it gets presented on its surface (processed)

Question 12

What binds to the processed antigens presented on the B cell?

Answer 12

T helper cells bind to processed antigens

Question 13

What do the T helper cells do when they bind to the processed antigens on the B cell?

Answer 13

stimulate B cell to divide by mitosis to form clone of identical B cells, all of which produce antibody that’s specific to foreign antigen

Question 14

What is the process of the antigen being recognised to B cell clones being made called?

Answer 14

clonal selection

Question 15

What does clonal selection account for?

Answer 15

body’s ability to respond rapidly to any of the vast number of antigens

Question 16

In practice how may different proteins are on the surface of a typical pathogen? (qualitative)

Answer 16

many

Question 17

What else can some pathogens produce?

Answer 17

toxins

Question 18

Example of a pathogen that produce toxins?

Answer 18

bacterium that cause cholera

Question 19

What does each toxin molecule act as?

Answer 19

an antigen

Question 20

What are the antibodies produced by the clones of the B cell called?

Answer 20

monoclonal antibodies

Question 21

What can the clone cell develop into? (2)

Answer 21

plasma cells
OR
memory cells

Question 22

What do plasma cells do?

Answer 22

secrete antibodies usually into blood plasma

Question 23

How long do plasma cell survive for?

Answer 23

a few days

Question 24

How many antibodies can each plasma cell make each second?

Answer 24

around 2000 antibodies

Question 25

What do the antibodies produced by the plasma cells lead to?

Answer 25

destruction of antigen

Question 26

What are the plasma cells responsible for?

Answer 26

immediate defence of body against infection

Question 27

What type of response is the production of antibodies + memory cells?

Answer 27

primary immune response

Question 28

What response are memory cells responsible for?

Answer 28

secondary immune response

Question 29

How long do memory cells live for in comparison to plasma cells?

Answer 29

live considerably longer, often for decades

Question 30

What do memory cells not produce directly?

Answer 30

do not produce antibodies directly

Question 31

Where do memory cells circulate?

Answer 31

in the blood + tissue fluid

Question 32

What happens when a memory cell encounters the same antigen at a later date?

Answer 32

divide rapidly + develop into plasma cells + more memory cells

Question 33

What do the plasma cells produced by the memory cells do?

Answer 33

produce antibodies needed to destroy the pathogen

Question 34

What do the new memory cells produced by the memory cell do?

Answer 34

circulate in readiness for any future infection

Question 35

What sort of immunity do memory cells provide?

Answer 35

long-term immunity against original infection

Question 36

What do memory cells ensure?

Answer 36

new infection destroyed before it can cause harm- + individuals often totally unaware they have been infected