Infection and Response Flashcards
(20 cards)
What is a pathogen?
A disease causing mircoorganism.
How can a virus cause disease?
Viruses live and reproduce inside cells, causing cell damage.
How can bacteria cause disease?
When bacteria reproduce, they produce toxins, which damage tissues.
What are three viral diseases and their effects?
Measles: fever and red skin rash.
HIV: flu-like symptoms, leads to aids.
Tobacco mosaic virus: affects growth due to lack of photosynthesis.
What are two bacterial diseases and their effects?
Salmonella: fever, abdominal cramps, vomiting and diarrhoea.
Gonorrhoea: Yellow discharge from the penis or vagina.
What are three fungal diseases?
Rose black spots, athletes foot and thrush.
How can diseases interact?
- Defects in the immune system.
- Viruses living in cells.
- Immune reactions.
- Physical illness leading to mental illness.
What are the four lines of defence against infection?
Skin, nose, trachea and bronchi (by producing mucus) and stomach.
How do lymphocytes destroy pathogens?
They produce antitoxins binding to the toxins produced by some pathogens (usually bacteria), neutralising toxins and produce antibodies targeting and destroying specific pathogens by binding to antigens (proteins) on the pathogens’ surfaces.
How do phagocytes destroy pathogens?
They are attracted to areas of infection. It surrounds a pathogen and engulfs it. Enzymes digest and destroy the pathogen.
How does a vaccine work?
Intoduce small quantities of dead or inactive pathogen, white blood cells are stimulatied to produce antibodies. If the same pathogen re-enters the body, white cells respond quickly, destroying the pathogen.
What is the use of antibiotics?
To cure bacterial diseases by killing infective bacteria inside the body.
What is the use of painkillers?
They are used to treat symptoms of a disease.
What are the stages in drug development?
- Preclinical testing uses cells, tissues, and living animals to test for toxicity at dosages.
- Clinical trials using healthy volunteers to test toxicity at different doses.
- Using larger groups to test effectiveness and toxicity at different dosages.
How are clinical trials carried out?
- Very low doses of the drug are given at the start of the clinical trial.
- If the drug is found to be safe, further clinical trials are carried out to find the optimum dose for the drug.
In ‘blind trials’, patients are unaware of dose and ‘double blind’ trials, neither patient nor doctor is aware of dose, some patients are given a placebo.
What is the role of a placebo?
It is a fake drug to test for the effectiveness of the real drug in comparisons.
What are monoclonal antibodies?
Human-made, identical copies of one type of antibody.
How do plants prevent disease?
By closing their stomatas or increasing thickness of cell walls.
How are plants affected by a lack of nitrate?
They will have stunted growth and yellowing of leaves.
How are plants affected by a lack of magnesium?
The plant is limited in terms of its photosynthetic ability, and the plant growth is compromised with leaves turning yellow while the veins may remain green.
