communicable diseases

Question 1

what is a communicable disease

Answer 1

a disease caused by a pathogen , which can be passed between animals or plants

Question 2

what is a pathogen

Answer 2

a disease cauing microorganism

Question 3

how do bacteria cause diseases

Answer 3

one inside the body, they divide rapidly by binary fission. they kill cells and produce harmful toxins

Question 4

how do viruses cause diseases

Answer 4

they invade and reproduce inside living body cells,leading to cell damage

Question 5

give 3 ways in which pathogens can be spread

Answer 5

.by air
.by water
.by direct contact

Question 6

give 4 ways in which the spread of pathogens can be reduced

Answer 6

.hygiene
.removing vectors
.vaccination
.reducing contact,with infected individuals

Question 7

why is it especially important to prevent the spread of viral diseases

Answer 7

scientists have not yet developed cures for many viral diseases

Question 8

what is measels

Answer 8

serious viral disease that can cause blindness and brain damage. the main symptoms are a fever and a red skin rash

Question 9

how is measels spread

Answer 9

by air- through the inhalation of droplets from coughs and sneezes

Question 10

what is HIV/ aids

Answer 10

a virus which attacks and damages the immune system until it can no longer function properly

.aids is the condition reuslting from a long term HIV infection. there is no cure or vaccine for HIV/AIDS

Question 11

how is HIV spread

Answer 11

direct sexual contact and the exchange of bodily fluids

Question 12

how can the spread of HIV/AIDS be prevented

Answer 12

.use of condoms
.screening of blood for transfusions
.not sharing needles
.bottle feeding by HIV-positive mothers
.use of drugsto prevent developtment of AIDS

Question 13

what is tobacco mosaic virus

Answer 13

a plant pathogen which causes leaf discolouration when cells are damaged.

affected areas cannot photosynthesise, reducing the crop yield. As there is no treatment , farmers grow TMV resistant crop strains to avoid infection

Question 14

how is tobacco mosaic virus spread

Answer 14

contact between affected and healthy plants.
insects may act as vectors which transfer the virus between different plants

Question 15

what is salmonella

Answer 15

a type of bacteria found in raw meat, poultry and eggs. if they enter the body via food poisining , they can affect natural gut bacteria.

Question 16

what are the symptoms of salmonella food poisining

Answer 16

.fever
.abdominal cramping
.vommiting
.Diaorreah

.may be fatal in very young or elderly populations due to risk of dehydration

Question 17

how can the spread of salmonella be prevented

Answer 17

.vaccinating animals intended for consumptiom
.keep raw meat away from cooked meat
.disinfect hands and surfaces after contact with raw meat
.thouroughly cook meat

Question 18

what is gonorreah

Answer 18

a sexually transmitted bacterial infection.

early symptoms include yellow/green discharge from genitals and painful urination, although it may be symptomless

its spread can be controlled through the use of antibiotics and using condoms.

Question 19

what is rose black spot

Answer 19

a fungal disease which causes purple or black spots to develop on rose leaves.

It reduces the area of the leaf which is available for photosynthesis and causes leaves to turn yellow and drop prematurely

Question 20

how is the rose black spot fungus spread

Answer 20

fungal spores are spread by the wind and in water

Question 21

how can rose black spot be treated

Answer 21

.using fungicides
.destroying infected leaves

Question 22

what is malaria

Answer 22

a disease caused by protist pathogens

carried out from host to host by mosquitos , and the protists enter the human bloodstream when they feed.

symptoms includefever and shaking, and it may also be fatal in some cases

Question 23

how can the spread of malaria be reduced

Answer 23

.using insecticides
.using insect nets to avoid bites
.prevent mosquitobreeding by removing stagnant water
.antimalarial drugs

Question 24

how does the skin prevent pathogens from entering the body

Answer 24

. acts as a physical barrier

.scab formation,after skin is cut,wounded

.antimicrobial secretions which can kill pathogens

.healthy skin flora compete with pathogens and act as a additional barrier

Question 25

how does the respiratory system prevent pathogens from entering the body

Answer 25

. nose- has hairs and mucus which trap pathogens .trachea and bronchi- have mucus that traps pathogens. cilliated cells move mucus to the mouth so it can be swallowed.

Question 26

how does the stomach prevent pathogens from infecting the body

Answer 26

.secretes hydrochloric acid- kills any pathogens present

Question 27

how does phagocytosis protect us against disease

Answer 27

whiteblood cells , ingest and destroy pathogens, so they cannot infect more cells

Question 28

how does antibody production protect us against disease

Answer 28

whiteblood cells produce antibodies , which are complementry to a specific antigen on a pathogen. the uilding of antibodies to antigens cause pathogens to clump together ,making them easier to destroy.

Question 29

how does antitoxin production protect us against disease

Answer 29

antitoxins bind to toxins released by pathogens and nuetralise them.

Question 30

what is a vaccination

Answer 30

contain a dead or inactivated form of the pathogen which stimulates white blood cells to produce complementary antibodies to the pathogen

Question 31

what is a herd community

Answer 31

if a sufficiently high population are immune to a disease , the spread of this disease will be limited

Question 32

what are the advantages of vaccinations

Answer 32

.they have eradicated many deadly diseases .many epidemics can be prevented by vaccinations .herd immunity protects those who cannot have vaccinations

Question 33

what are the disadvantages of vaccinations

Answer 33

.not guaranteed to work-might not protect against multiple strains of pathogen .may be side affects or adverse reactions

Question 34

what drugs are used to cure some bacterial diseases

Answer 34

antibiotics-they can kill bacterial pathogens inside the body

Question 35

how do anitbiotics work

Answer 35

pencilin kill bacteria pathogens inside the body,but do not kill human cells.whilst some antibiotics kill a wide range of bacteria,it is important that the right antibiotic is used for specific bacteria

Question 36

why can antibiotics not be used to treat viral diseases

Answer 36

antibiotics have no affect on viral pathogens as they live, inside the hosts cells. Therfore it is difficult to design drugs , that would kill the virus and not destroy human cells at the same time.

Question 37

what is antibiotic resistance

Answer 37

occurs when mutations lead to individual bacteria , being resistant to an antibiotic. these bacteria are able to survive ,reproduce and pass on their alleles,leading to a greater proportion of anitbiotic-resistant bacteria.

Question 38

how can we prevent anitbiotic resistance

Answer 38

. avoid overuse and unescassary use of antibiotics .finish antibiotic courses-to ensure all bacteria is killed

Question 39

what effect do painkillers have on infectious diseases

Answer 39

painkillers can only treat the symptoms but do not kill pathogens

Question 40

what plant is the heart drug digitalis extracted from

Answer 40

foxgloves

Question 41

what painkillers originates from a compound found in willow bark

Answer 41

aspirin

Question 42

what antibiotic was discovered by alexandar fleming from a type of mould

Answer 42

penicillin

Question 43

what are the 4 qualities of a good medicine

Answer 43

.effective .safe .stable .able to be taken in and removed easily

Question 44

what 3 main factors are tested for when developing new drugs

Answer 44

.toxicity .efficiacy .Dose

Question 45

how is precilinical testing carried out

Answer 45

in a labrotary- uses cells,tissues and live animals

Question 46

how is clinical testing carried out

Answer 46

uses healthy volunteers and patients. Firstly the drug is tested at a low dose on healthy people- then tested on larger to find the optimum dose

Question 47

what is the difference between a single-bond and a double-blind trials

Answer 47

in a single-blind trial , only

Question 48

what is a peer-review

Answer 48

where the results of drug-trials are checked over by scientists knowledgeable in this field