T lymphocytes

Question 1

how many stages are there in the response of T lymphocytes to infection?

Answer 1

5

Question 2

what’s the first stage of T-lymphocytes response to infection by a pathogen?

Answer 2

pathogens invade body cells or are taken in by phagocytes.

Question 3

what’s the second stage of T-lymphocytes response to infection by a pathogen?

Answer 3

the phagocyte places antigens from the pathogen on its CSM

Question 4

what’s the third stage of T-lymphocytes response to infection by a pathogen?

Answer 4

receptors on a specific helper T cell fit exactly onto these antigens.

Question 5

what’s the fourth stage of T-lymphocytes response to infection by a pathogen?

Answer 5

this attachment activates the T cell to divide rapidly by mitosis and form a clone of genetically identical cells.

Question 6

What are the 4 things that the cloned T cells do to fight the pathogen after they have been created through mitotic division?

Answer 6

they develop into memory cells that enable a rapid response to future infections by the same pathogen.

stimulate phagocytes to engulf pathogens by phagocytosis.

stimulate B cells to divide and secrete their antibody.

activate cytotoxic T cells.

Question 7

how do cytotoxic t cells kill infected cells?

Answer 7

they produce a protein named perforin which makes holes in the CSM. This makes the CSM freely permeable to all substances resulting in the cell dying.

Question 8

where do t cells mature?

Answer 8

thymus gland

Question 9

are t cells involved in cell-mediated immunity or humoral immunity?

Answer 9

cell-mediated immunity

Question 10

what is an antigen?

Answer 10

a part of an organism that is recognised as non-self by the immune system and so stimulates an immune response.

Question 11

where do b cells mature?

Answer 11

bone marrow

Question 12

are be cells involved in humoral or cell-mediated immunity?

Answer 12

humoral

Question 13

why is humoral immunity named humoral immunity?

Answer 13

humor is an old word for body fluids and humoral immunity involves antibodies which are found in body fluids.

Question 14

how many steps are there regarding the role of b cells in immunity?

Answer 14

7

Question 15

what’s the first step in the role of b cells in immunity?

Answer 15

the surface antigens of invading pathogens are taken up by a b cell

Question 16

what’s the second step in the role of b cells in immunity?

Answer 16

the b cell processes the antigens and presents them on its surface

Question 17

what’s the third step in the role of b cells in immunity?

Answer 17

helper t cells attach to the processed antigens on the b cell therby activating the b cell

Question 18

what’s the fourth step in the role of b cells in immunity?

Answer 18

the b cell is now activated to divide by mitosis to give a clone of plasma cells

Question 19

what’s the fifth step in the role of b cells in immunity?

Answer 19

the cloned plasma cells produce and secrete the specific antibody that exactly fits the antigen on the pathogen’s surface

Question 20

what’s the sixth step in the role of b cells in immunity?

Answer 20

the antibody attaches to antigens on the pathogen and destroys them

Question 21

what’s the sixth step in the role of b cells in immunity?

Answer 21

some b cells develop into memory cells. these can respond to future infections by the same pathogen by dividing rapidly and developing into plasma cells that produce antibodies. this is the secondary response