B Cells

Question 1

Where are B cells made and matured?

Answer 1

bone marrow

Question 2

What kind of response involves B cells and antibodies?

Answer 2

humoral response

Question 3

What are the properties of antibodies?

Answer 3

-soluble
- transport in bodily fluids

Question 4

What happens when antigens collide with B- cells? How are B cells activated?

Answer 4

• antigens in blood collide with their complementary antibody on a B cell
• b cell undergoes endocytosis with the antigen and presents it on its cell surface membrane
• when a b cell collides with a t-helper cell, this activates the b cell to go through clonal expansion + differentiation (clonal selection)

Question 5

What is clonal expansion and clonal selection?

Answer 5

• b cells undergoing mitosis to make large numbers of cells which differentiate into either plasma cells or memory b cells

Question 6

What do plasma cells do?

Answer 6

• plasma cells make antibodies which are complementary in shape to that particular antigen

Question 7

What do memory B cells do?

Answer 7

• memory cells can divide rapidly into plasma cells if cells are reinfected with the same pathogen to make large numbers of antibodies rapidly

Question 8

What are the differences between memory b cells and plasma?

Answer 8

• memory cells cannot make antibodies; they can divide by mitosis and then differentiate into plasma cells rapidly if they collide with an antigen they have previously encountered
• can live for decades in the body whereas plasma cells are short lived

Question 9

What kind of proteins are antibodies?

Answer 9

• quaternary structure proteins (4 polypeptide chains)

Question 10

What is agglutination?

Answer 10

• antibodies are flexible + can bind to multiple antigens + clump them together
• makes it easier for phagocytes to locate and destroy pathogens

Question 11

What is passive immunity?

Answer 11

• antibodies are introduced into the body
• pathogen doesn’t enter the body; plasma cells and memory cells are not made

Question 12

Does passive immunity give long term immunity?

Answer 12

-no
- eg - mother passing on antibodies to baby when breastfeeding

Question 13

What is active immunity?

Answer 13

• immunity created by own immune system after exposure to a pathogen/ its antigen
• 2 types: natural/ acrtificial

Question 14

What is natural active immunity?

Answer 14

• following an interaction + creation of body’s own antibodies and memory cells

Question 15

What is artificial active immunity?

Answer 15

• following the introduction of a weakened version of the pathogen or antigen via a vaccine