communicable diseases

Question 1

what is a pathogen?

Answer 1

a microorganism that causes disease.

Question 2

what are the four types of pathogen?

Answer 2

• fungi
• virus
• bacteria
• protoctista

Question 3

name the pathogen that causes TB

Answer 3

bacteria

Question 4

name one characteristic of TB

Answer 4

killing of cells and tissues especially lungs

Question 5

what pathogen causes meningitis?

Answer 5

bacteria

Question 6

name one characteristic of meningitis.

Answer 6

causes membranes to swell and potentially causing damage to important areas such as spinal cord and brain

Question 7

what causes ring rot?

Answer 7

bacteria

Question 8

name one characteristic of ring rot

Answer 8

decayed vascular tissue

Question 9

what causes HIV/AIDS?

Answer 9

virus

Question 10

what is one characteristic of HIV/AIDS

Answer 10

damages the immune response

Question 11

what is direct transmission?

Answer 11

passing a pathogen from host to host.

Question 12

define indirect transmission?

Answer 12

passing a pathogen from host to host via a vector

Question 13

what are the direct ways of transmitting a pathogen?

Answer 13

• physical contact
• faecal/oral
• droplet infection
• spores

Question 14

what factors affect transmission?

Answer 14

• overcrowding
• poor ventilation
• poor health
• poor diet
• homelessness

Question 15

what is Callose?

Answer 15

a large polysaccharide deposit that blocks old phloem sieve tubes

Question 16

what is a passive defence?

Answer 16

defences before infection occurs

Question 17

what are the physical defences against pathogens?

Answer 17

• cellulose cell wall
• lignin thickening of cell walls
• waxy cuticles
• bark
• stomatal closure
• callose
• tylose formation

Question 18

what is inflammation?

Answer 18

swelling and redness of tissue caused by infection

Question 19

what is a mucous membrane?

Answer 19

specialised epithelial cells covered by mucus

Question 20

what are primary defences?

Answer 20

those that prevent pathogens entering the body

Question 21

what are some examples of primary defences in the body?

Answer 21

• the skin
• blood clotting and skin repair
• mucous membranes
• coughing and sneezing
• inflammation

Question 22

what is an antigen presenting cell?

Answer 22

a cell that isolates the pathogen and presents it so it can be recognised by the immune system

Question 23

what is clonal selection?

Answer 23

selection of B or T cells that are specific to the antigen

Question 24

what are cytokines?

Answer 24

hormone like molecules that are used in cell signalling in order to trigger the immune response

Question 25

what is a neutrophil?

Answer 25

a type of white blood cell that engulfs foreign matter and digests it

Question 26

what are opsonins?

Answer 26

proteins that bind to the antigen on the pathogen and allow phagocytes to bind

Question 27

what are antibodies?

Answer 27

specific proteins that are released by plasma cells that can attach to pathogenic antigens

Question 28

what are B memory cells?

Answer 28

cells that remain in the blood for a long time providing long term immunity

Question 29

what is clonal expansion?

Answer 29

an increase in the number of cells by mitotic cell division

Question 30

what are interleukins?

Answer 30

signalling molecules that are used to communicate between white blood cells

Question 31

what are plasma cells?

Answer 31

derived from B lymphocytes

Question 32

what are t-helper cells?

Answer 32

cells that release signalling molecules to stimulate the immune response.

Question 33

what are t-killer cells?

Answer 33

cells that attack and destroy our own body cells that are infected by the pathogen

Question 34

what is active immunity?

Answer 34

where the immune system is activated and manufactures its own antibodies

Question 35

what is artificial immunity?

Answer 35

immunity that is achieved as a result of medical intervention

Question 36

what is passive immunity?

Answer 36

immunity achieved when antibodies are passed to the individual through breastfeeding

Question 37

what is natural immunity?

Answer 37

immunity achieved through normal life processes.