Biology Y9 Pathogens Flashcards
(35 cards)
measles
virus spread by inhalation of droplets produced by infected people when sneezing and coughing
symptoms:
fever, red skin rash, fatal complications (blindness, braindamage)
so young children are vaccinated against
HIV
human immunodeficiency virus
spread by unprotected sexual contact, exchange of bodily fluids (needles) + breastmilk sometimes
symptoms are flulike at first, but virus attacks the body’s immune cells, leading to AIDS - where immune system is so damaged that it cannot fight off infection/cancers
no cure, but treatment to reduce it to undetectable
TMV
Tobacco Mosaic Virus
spread by direct contact of plants with infected plant material, animal and plant vectors and soil (pathogen can remain in the soil for DECADES)
symptoms are mosaic pattern of discolouration of leaves (chlorophyll destroyed) - reducing plants ability to photosynthesise - will affect growth
Salmonella
bacteria spread by being in / on ingested food
the bacteria and its toxins cause:
fever, abdominal cramps, vomiting, diarrhoea
poultry are vaccinated against salmonella bacteria to control spread
+ cook food properly, wash hands/wear gloves, ensure food is in date and wash food
Gonorrhoea
bacteria spread by direct sexual contact - an STD
causes: thick yellow/green discharge from the vagina/penis, and pain when urinating
treated with antibiotics (although many resistant strains have appeared), and barrier methods of contraception (condoms)
rose black spot
fungi/spores spread by water and wind
cause purple/black spots on leaves, which turn yellow and drop early
reduce ability to photosynthesize - affect growth
either treat with fungicides or remove/destroy affected leaves
malaria
protist
spread by mosquitos feeding on the blood of people and spreading the protist pathogen - act as a disease vector
symptoms are cycling fevers, shaking, but can be fatal because of damage to red blood cells
prevented by stopping mosquito vectors breeding, using mosquito nets to prevent bites and using anti malarial medicine
controlling spread of communicable disease (4 ways)
- hygiene: handwashing, disinfecting surfaces, keeping raw meat separate, covering mouth when coughing/sneezing
- isolation of infected individuals
- controlling population of vectors
- vaccination
what is health
a state of physical and mental wellbeing
what contributes to poor health
diet (e.g. starvation), stress (e.g. mental health) and life situations (e.g. living environment)
communicable disease
a disease that can be spread from person to person
how can a disease spread (3 ways)
pathogens, an animal or object
risk factor
something that increases your chance of getting a disease
incidence
the number of people diagnosed with a particluar disease in a particular population of people at a particular time
NUMBER OF NEW DIAGNOSES
prevalence
the number of people who have a particular condition regardless of whether they were just diagnosed or even whether they have been diagnosed at all
mortality
the number of deaths per unit of population from a specific disease
egs of risk factos
L: smoking, excessive alcohol consumption, poor diet and lack of exercise
E: exposure to ionising radiation and exposure to carcinogens
I: genes
sampling
taking a smaller representation of the whole
pathogen (and what can be a pathogen)
a microorganism that causes an infectious disease
can be bacteria, viruses, fungi and protists but most are not
are viruses alive? do they have cells?
aren’t, don’t
how do bacteria multiply
by binary fission
examples of airborne transmission
viruses and bacteria travel in droplets and fungi by airborne spores
examples of direct touch
surfaces, skin, sexual transmission, wounds and needles
examples of unclean food/water transmission (3) (THINK)
fungal spores in water splashes, raw and undercooked food, contaminated water and sewage
