Disease and Immune

Question 1

what is a disease ?

Answer 1

condition that impairs the normal functioning of an organism

Question 2

what is a communicable disease ?

Answer 2

disease that can be spread

Question 3

what organism does ring rot affect ?

Answer 3

potatoes, tomatoes

Question 4

what organism does black sigatoka affect ?

Answer 4

banana plants

Question 5

what organism does bacterial meningitis affect ?

Answer 5

just humans

Question 6

name the three bacterial diseases

Answer 6

TB / bacterial meningitis / ring rot

Question 7

name the three virus diseases

Answer 7

HIV / influenza / tobacco mosaic virus

Question 8

name the three fungus diseases

Answer 8

black sigatoka / ringworm / athlete’s foot

Question 9

name the three protocist diseases

Answer 9

potato blight / malaria

Question 10

what several ways can direct transmission occur ?

Answer 10

droplet inflection / sexual intercourse / touching infected organism

Question 11

give examples of pathogens which use direct transmission

Answer 11

• HIV (sex)

- athlete’s foot (touch)

Question 12

what is indirect transmission ?

Answer 12

disease is transmitted via an intermediate

Question 13

name the intermediates for indirect transmission

Answer 13

air / water / food / vector (another organism)

Question 14

give examples of pathogens which use indirect transmission

Answer 14

• potato blight (spores in air, then water)

- malaria (mosquito as vectors)

Question 15

what are the three factors that affect disease transmission ?

Answer 15

living conditions climate / social factors

Question 16

how does skin protect from pathogens ?

Answer 16

• acts as physical barrier

- produces antimicrobial chemicals that lower pH, inhibiting pathogen growth

Question 17

how does mucous membranes protect from pathogens ?

Answer 17

(exposed areas) - secrete mucus which traps pathogens and contains antimicrobial enzymes

Question 18

how does blood clotting protect from pathogens ?

Answer 18

plug wounds, preventing pathogen entry

Question 19

how does expulsive reflexes protect from pathogens ?

Answer 19

expels foreign objects

Question 20

what is inflammation characterized as ?

Answer 20

redness / swelling / heat

Question 21

what triggers inflammation ?

Answer 21

when tissue is damaged

Question 22

what happens when tissue is damaged ?

Answer 22

mast cells are activated - releasing histamines and cytokines

Question 23

what do histamines do ?

Answer 23

• dilate blood vessels, increasing heat at damage site, stops pathogens reproducing
• increases permeability of capillary walls to let neutrophils to pathogens

Question 24

what do cytokines do ?

Answer 24

attract white blood cells

Question 25

name some plant physical defences against pathogens

Answer 25

- waxy cuticle - cell walls - callose

Question 26

describe how callose defends plants from pathogens

Answer 26

- callose deposited between cell wall and membrane in times of stress - callose makes it harder for pathogen to enter cells

Question 27

name some plant chemical defences against pathogens

Answer 27

- produce antimicrobial chemicals to kill / inhibit growth of pathogen - secrete chemicals that are toxic for insects to reduce plant viruses carried by insect vectors

Question 28

what are the two types of phagocytes ?

Answer 28

neutrophil and macro phage

Question 29

what is a phagosome ?

Answer 29

pathogen enclosed in a membrane in a phagocyte

Question 30

what is a phagolysosome ?

Answer 30

lysosome fused with a phagosome

Question 31

phagocytes are ...

Answer 31

non - specific

Question 32

what is special about macrophages ?

Answer 32

they keep some of pathogens antigens, which they attach to the glycoproteins MHC

Question 33

what does MHC stand for ?

Answer 33

major histocompatibility complex

Question 34

what does MHC do ?

Answer 34

- moves to plasma membrane of macrophage and puts antigens into membrane - cell is now antigen - presenting

Question 35

what does antigen - presenting mean ?

Answer 35

'shows' antigens to cells of specific immune system (lymphocytes), activating them

Question 36

what are opsonins ?

Answer 36

- bind to pathogens and identify them to phagocytes | - most are antibodies / immunoglobulins produced by lymphocytes

Question 37

define natural immunity

Answer 37

occurs naturally without medical treatment

Question 38

what processes do T lymphocytes undergo ?

Answer 38

clonal selection + clonal expansion

Question 39

what is clonal selection ?

Answer 39

- antigen (from APCs) binds to complementary receptors of T lymphocyte - (T lymphocytes are specific)

Question 40

what is clonal expansion ?

Answer 40

divides to produce clones of itself

Question 41

what is function of T helper cells ?

Answer 41

release substances (interleukins) to activate B lymphocytes and T killer cells

Question 42

what is function of T killer cells ?

Answer 42

attach and kill cells infected with a virus

Question 43

what is function of T regulatory cells ?

Answer 43

- suppress immune response from other WBCs | - this helps stop immune system cells attacking host's body cells

Question 44

what do some T lymphocytes become... ?

Answer 44

memory cells

Question 45

how are B lymphocytes activated ?

Answer 45

- complementary antigen binds to antibodies on lymphocyte (antigen-antibody complex) - interleukins released from T helper cells binds to B lymphocyte receptors

Question 46

what happens to B lymphocytes once activated ?

Answer 46

divide by mitosis into plasma cells / memory cells

Question 47

what is the function of plasma cells ?

Answer 47

secrete antibodies

Question 48

what are the three things antibodies do ?

Answer 48

agglutinate / neutralise toxins / prevent pathogen from binding to human cells

Question 49

what does it mean that antibodies agglutinate pathogens ?

Answer 49

- has two binding sites, so can bind to two, causing them to clump - means phagocytes can engulf multiple at a time - this antibodies are known as agglutinins

Question 50

why is primary response slow ?

Answer 50

- not many B lymphocytes ready to make antibodies

Question 51

what cells are activated in primary response ?

Answer 51

B and T lymphocytes

Question 52

what cells are activated in secondary response ?

Answer 52

memory cells

Question 53

what is the nucleus + cytoplasm of a neutrophil described as ?

Answer 53

multi - lobed + grainy

Question 54

what does a lymphocyte look like ?

Answer 54

small, nucleus takes up most of cell

Question 55

what is the biggest white blood cell called ?

Answer 55

monocyte

Question 56

what is an autoimmune disease ?

Answer 56

immune system treats self antigens as foreign, and launches an immune response against its own tissue

Question 57

what is herd immunity ?

Answer 57

vaccinating most people in a community

Question 58

what is immunization ?

Answer 58

process by which you develop immunity

Question 59

what is vaccination ?

Answer 59

administration of antigens

Question 60

why are booster vaccines given later ?

Answer 60

to make sure memory cells are produced

Question 61

why does the influenza vaccine change every year ?

Answer 61

antigens of influenza changes regularly, so will not be recognized by memory cells

Question 62

give function of variable region in antibody

Answer 62

antigen binding site

Question 63

give function of constant site in antibody

Answer 63

binding site to receptors of phagocytes

Question 64

give function of disulfide bridge in antibody

Answer 64

holds polypeptide chains together

Question 65

give function of hinge region in antibody

Answer 65

allows flexibility when binding

Question 66

state the 4 differences between active and passive immunity

Answer 66

- active requires exposure to antigens (passive doesn't) - active takes for protection to develop, active is immediate - active is long term, passive is short term - active memory cells produced, passive there aren't

Question 67

define health

Answer 67

disease free, good nutrition, physical mental social well being

Question 68

what to say with growth of bacteria

Answer 68

multiply / divide not growth

Question 69

what is irradiation

Answer 69

way of destroying pathogen DNA

Question 70

what is pickling

Answer 70

lower pH to denature pathogen enzymes

Question 71

increased fats cause

Answer 71

stroke