B5 communicable diseases Flashcards
what are pathogens?
microorganisms that cause disease
name 4 types of pathogens
protists
viruses
fungi
bacteria
How do viruses cause disease
they take over the cells of your body they live and reproduce inside the cells damaging and destroying them
what is bacteria and how does it cause disease
Bacteria is single celled microorganism, they divide rapidly by splitting into two(binary fission)
they produce toxins which make you feel ill
how can pathogens spread
air-droplet infection
direct contact—> eg HIV/AIDS
hepatitis
STDs
water—>eg. salmonellosis
cholera
how can the spread of disease be prevented
hygiene
isolating infected individuals
destroying vectors
vaccination
what is a vaccine and how does it work
introducing a small amount of harmless form of a specific pathogen, so if you come in contact with the live pathogen you will not become ill as your immune system will be prepared
what are the symptoms of measles
fever and red skin rash
how is measles spread
by the inhalation of droplets from coughs and sneezes
What does HIV/AIDS cause
mild flue like illness to begin with. HIV attacks the immune system. It remains hidden in the immune system until it becomes so damaged it can no longer deal with the symptoms—>this is now AIDS
How is HIV spread
sexual contact
exchange of body fluids
mother to child through breast milk
how to prevent the spread of HIV
use of condoms
not sharing needles
what are the symptoms of the tobacco mosaic virus
distinctive mosaic pattern of discoloration on plant leaves
the affected parts of the plant do not photosynthesise
How is TMV spread?
by direct contact between diseased plant material and helathy plants
insects can be vectors
how can we prevent the spread of TMV
NO CURE
good field hygiene
pest control
Where can salmonella bacteria be found
guts of many animals
poultry
eggs/egg products
Why is it a problem for salmonella to enter the body
It disturbs the balance of our natural gut bacteria
what are the symptoms of Salmonella
develop within 8-72 hours of eating the infected food
abdominal cramps
vomiting
diarrhoea
treatment of salmonella
no antibiotics required
How can the spread of salmonella be prevented
Vaccinate poultry against salmonella
keep raw chicken away from food that is uncooked
wash surfaces and hands well after handling the poultry
cook chicken thoroughly
what is gonorrhoea
a sexually transmitted disease
how is gonorrhoea spread
unprotected sex with an infected person
what are the symptoms of gonorrhoea
thick yellow/green discharge from the vogi/penis
pain on urination
what can untreated gonorrhoea lead to
long term pelvic pain
infertility
ectopic pregnancies
babies born from infected mothers may have severe eye infections and even in extreme cases go blind
how can the spread of gonorrhoea be prevented
antibiotics
reducing number of sexual partners
use methods of contraception
name a type of bacteria that causes a bacterial disease in plants
Agrobacterium tumefaciens , it causes crown galls
How does this plant bacterium affect plants
the bacteria inserts plasmids into the plant cells and cause a mass of undifferentiated genetically modified cells to grow
How do scientist use bacteria in plants
to genetically modify plants, naturally infecting them to give them new added genes, these carry the desirable characteristics
name a fungal disease that affects HUMANS
athletes foot-skin fungi
how can u treat skin fungal diseases
antifungal drugs
name a plant disease caused by fungi
Rose black spot
How does RBS affect plants
blue/black spots develop on rose leaves
leaves often turn yellow and drop
->lower surface area of leaves available for photosynthesis
How can RBS be prevented
removing/burning affected leaves/stems
chemical fungicides
Horticulturists bred type of roses that are relatively resistant to RBS
name an example of protist caused disease
malaria
symptoms of malaria
fever
shaking
death
how can the spread of malaria be prevented
using insecticide impregnated nets-prevents mosquitoes from biting humans and spreading the protists
using insecticides to kill the mosquitoes
preventing vectors from spreading(removing standing water)
antimalarial drugs that kill the parasites if they are bitten
what is herd immunity
if a large proportion of the population is immune to a disease, the spread of the pathogen is reduced and the disease may even disappear
difference between antibiotics and pain killers
pain killers only ease symptoms while antibiotics cure bacterial diseases
who discovered penicillin and how
Alexander Fleming-from penicillin mould
what are new medical drugs tested for
efficacy-effectiveness
dosage
toxicity
what is done during preclinical testing
testing on cell tissues /living animals
tested for efficacy toxicity and dosage
what is done during clinical trials
tested on healthy volunteers and patients-firstly low doses are given to healthy people in order to check for side effects
if proved safe it is then used on patients to see if it seems to be treating it
what happens during double blind trials
placebo—>tests the efficacy of he medicine
what are carcinogens
agents that cause cancer or significantly increase the chances of getting cancer
what is a tumour
forms when cells grow in an abnormal uncontrolled way
what is the difference between malignant and Benign tumours
benign:
uncontrollable cell growth in only one area of the body, so they do not invade other parts of the body
malignant:
this uncontrollable cells can spread around the body, invading neighbouring healthy tissues
–>cancer
what are some causes of cancer
genetics
carcinogens
ionising radiation
