B5 Flashcards
Bacteria vs virus
Bacteria is single called and small
Virus is even smaller, regular shaped, causes disease in all organisms
How bacteria causes disease
Divide rapidly by binary fission (splitting in two)
May produce toxins
Some directly damage your cells
How virus causes disease
Take over cells in your body
Live and reproduce inside cells, damaging and destroying them
How pathogens are spread
Air - droplets from coughs and sneezes that other people breathe in
Direct contact - sexual, cuts, scratches, needle punctures
Water/ food - contaminated
How to grow bacteria in a lab
- provide a culture medium (liquid or gel containing everything they need)
- pour agar gel into a petri dish
- sterilise everything
- inoculate the sterile agar with the microorganism
- incubate petri dish upside down
Safety precautions in growing bacteria (ascetic technique)
- Petri dish and agar gel must be sterilised. Glass dishes can be heated as the steam at high pressure sterilises it, plastic dishes are usually already sterilised, UV light can be used to kill bacteria
- sterilise inoculating loop by heating it until it is red hot then letting it cool down to room temperature
- put lid straight back on and stick it down to avoid contamination
- incubate at maximum 25 degrees (not body temperature)
What did Ignaz Semmelweis do
Discovered washing hands lowered death rates from childbed fever
How does hygiene prevent spread of communicable diseases
Wash hands
Use disinfectant
Keep raw meat isolated
Cough or sneeze into tissue
How does isolation prevent the spread of communicable diseases
Infected person should be isolated
Fewer people in contact with the pathogen, the less likely it will be spread on
How to prevent spread of vector diseases
Destroy/ control the number of vectors
How does vaccination prevent spread of disease
Doctors inject harmless amount of pathogen into body. If you come into contact with pathogen again, you will not become ill
Is measles virus, bacteria, fungal or protist
Virus
Cause, symptoms and treatment of measles
Symptoms = fever and red rash
Cause = inhalation of droplets from coughs or sneezes (very contagious)
Treatment = no treatment so infected people must isolate although young people are vaccinated against it
Other info = can cause blindness, brain damage or be fatal
Is HIV/aids virus, bacteria, fungal or protist
Virus
Symptoms of HIV/ aids
Mild flu and illness to begin
Attacks immune system and remains hidden s the body can’t deal with infections or certain cancers
How is HIV spread
Sexual contact and exchange of bodily fluids
Cure for HIV/ aids
No cure
Can be prevented through condoms, not sharing needles, screening blood & mothers bottle - feeding
Development of aids can be prevented through antiretroviral drugs
Is TMV virus, bacteria, fungal or protist
Virus
TMV symptoms
Mosaic pattern of discolouration on leaves as it kills cells, effects growth as leaves can’t photosynthesise
How TMV is spread
Direct contact between diseased plants and healthy plants