GCSE Revision 3/7 Flashcards
(72 cards)
How do viruses and bacteria grow
They reproduce rapidly when inside the body
How do bacteria make you feel ill
They produce toxins which damage the body cells
How do viruses make you feel ill
The reproduce inside cells, damaging/destroying them
How are pathogens spread through air (2)
Wind currents
Droplets carrying pathogens (among humans during coughing/sneezing)
How are pathogens spread through direct contact (4)
Sexually
Skin contact (cuts, scratches, needle punctures etc)
Vectors such as mosquitos when sucking blood
If a portion of diseased plant is left in a field it could infect the whole crop
How are pathogens spread through water (2)
Drinking contaminated water
Fungal spores in splashes of water can spread plant disease
Binary fission
The way in which bacteria multiply rapidly
Steps for growing cultures (5)
Use agar gel as a culture medium
Pour hot, sterile agar gel into petri dish
Inoculate the sterile agar, using a sterilised wire loop, with the bacteria
Provide warmth and oxygen to grow
Keep the dish incubated at no higher than 25ºC
How to keep culture uncontaminated (3)
Kill all the bacteria on the equipment by boiling solutions and agar and passing loop through flame to sterilise
Prevent microorganisms from the air getting into the petri dish by closing up the petri dish once inoculated
Prevent microorganisms leaving the petri dish after the experiment by disposing of the culture correctly
How to prevent bacterial growth (4)
Raising/lowering the temperature
Disinfectants (kill bacteria in environment)
Antiseptics (kill bacteria on skin)
Antibiotics (kill bacteria inside body)
Measles symptoms (2)
Fever
Red skin rash
How is measles spread
Droplet infection
How can measles be prevented
Vaccination
HIV symptoms
Flu-like
How is HIV spread (3)
Direct sexual contact
Infected blood (shared needles)
Breast milk
How can HIV be prevented (3)
Condoms
Screening blood before transfusion
Bottle-feeding babies
TMV symptoms (2)
Discolouration of the leaves
Destroys cells so the plant cannot photosynthesise
How is TMV spread (2)
Contact between diseased and healthy plants
Animal vectors
How can TMV be prevented (2)
TMV-resistant crops
Good field hygiene and pest control
Salmonella symptoms (4)
Fever
Abdominal cramps
Vomiting
Diarrhoea
How is salmonella spread (2)
Undercooked food
Poor food hygiene
How can salmonella be prevented (2)
Vaccinating chickens
Good food hygiene
Gonorrhoea symptoms (2)
Discharge
Pain on urination
How is gonorrhoea spread (2)
Unprotected sexual contact with an infected person