B5 Immunity

Question 1

what is an antigen

Answer 1

foreign protein that stimulates an immune response

Question 2

what is a pathogen

Answer 2

microorganisms that cause disease

Question 3

what is the process of phagocytosis

Answer 3

1 = phagocyte is attracted to the pathogen
2 = phagocyte engulfs the pathogen forming a vesicle
3 = lysosome moves towards the vesicle and fuses with it
4 = lysosome releases its lysozyme enzymes which hydrolyses the bacteria.

Question 4

what is self recognition

Answer 4

ability of the body to recognize its own body cells and the difference between them and abnormal cells

Question 5

non specific defence mechanisms

Answer 5

immediate response and is the same for all pathogens eg phagocytosis

Question 6

specific defence mechanisms

Answer 6

slower response and is different for each pathogen

Question 7

examples of physical defences

Answer 7

skin
eyes ( tears)
ear ( wax )
vagina ( acidic conditions )

Question 8

what are B lymphocytes

Answer 8

white blood cells
matured in bone marrow

Question 9

how do phagocytes activate T cells

Answer 9

antigens on the phagocyte will bind to complementary receptors on the t cell activating it

Question 10

what are the two types of T cells

Answer 10

helper t cells which stimulate phagocytosis
cytotoxic t cells which kill abnormal and foreign cells

Question 11

how are B cells activated

Answer 11

B cells have have different antibodies which are complimentary to different antigens. this activates the B cell and starts clonal selection

Question 12

what do B cells divide into

Answer 12

plasma cells which produce antibodies
memory cells used for secondary immune response

Question 13

what are the two immune responses

Answer 13

humoral response = B cells, clonal selection and production of monoclonal antibodies
cellular = T cells and other immune system cells (phagocytes)

Question 14

what are the purpose for memory cells

Answer 14

used in secondary immune response
if same pathogen enters the immune system will produce a quicker, stronger immune response.
gets rid of pathogen before you begin to show symptoms.

Question 15

what is active immunity and what are the two types

Answer 15

its when the immune system creates its own antibodies
the two types are artificial and natural

Question 16

what is natural active immunity

Answer 16

when baby becomes immune after a disease

Question 17

what is artificial active immunity

Answer 17

when the body becomes immune after a vaccine

Question 18

what is passive immunity and what are the two types

Answer 18

it is when antibodies are donated from another organism
the two types are artificial and natural

Question 19

what is natural passive immunity

Answer 19

when a baby gets immunity from the mother through the mothers milk

Question 20

what is artificial passive immunity

Answer 20

when you are injected with antibodies from another individual

Question 21

what are the features of a successful vaccination programme

Answer 21

must be economically available
few side effects
means of producing, storing and transporting the vaccine

Question 22

what is herd immunity

Answer 22

when a sufficiently large proportion of the population has been vaccinated to make it difficult for the pathogen to spread.

Question 23

what are the ethics of using vaccine

Answer 23

production may have use of animals
may have long term side effects
unknown health risks

Question 24

what are the features of HIV structure

Answer 24

matrix
lipid envelope
attachment proteins
capsid
reverse transcriptase enzyme

Question 25

how does HIV replicate

Answer 25

1 = A protein attaches to a receptor on cell membrane of T helper cell 2 = protein capsid fuses with cell surface membrane 3 = RNA and enzymes of HIV enter the T helper cell 4 = HIV'S reverse transcriptase converts the virus's RNA into DNA 5 = new DNA moves into T helper cell nucleus where it is inserted into cell's DNA 6 = HIV DNA in nucleus creates mRNA which has instructions for making viral proteins 7 = mRNA passes out of nucleus through a nuclear pore 8 = the viral proteins are assembled into new viruses which go to infect other cells.

Question 26

Steps of the Elisa Test

Answer 26

1 = a testing well with HIV antigen is present and patients blood sample is added to it. if blood has HIV antibodies it will bind to the antigen 2 = well needs to be washed out to remove any unbound antibodies 3 = monoclonal antibody with an enzyme attached with a coloured dye is added 4 = well needs to be washed out again after adding secondary antibody to remove any unbound secondary antibody 5 = solution is added to well which is able to react with the enzyme on secondary antibody 6 = if solution changes colour person has HIV specific antibodies and their blood is infected with HIV

Question 27

how are monoclonal antibodies used in cancer treatment