4.3 Infection and response Flashcards
(30 cards)
What are pathogens?
Pathogens are microorganisms that cause infectious diseases. They include viruses bacteria
How can pathogens be spread?
Pathogens can be spread by direct contact through water
How do bacteria cause illness?
Bacteria reproduce rapidly and produce toxins that damage tissues and make us feel ill.
How do viruses cause illness?
Viruses live and reproduce inside cells causing cell damage.
What are the symptoms and transmission of measles?
Measles causes fever and a red skin rash and is spread by inhaling droplets from coughs and sneezes.
How is HIV transmitted and what does it do to the body?
HIV is spread through sexual contact or by sharing infected needles. It attacks immune cells and can lead to AIDS.
What is Tobacco Mosaic Virus (TMV) and how does it affect plants?
TMV causes a mosaic pattern on leave reducing photosynthesis and plant growth.
How is salmonella spread and what are its symptoms?
Spread by contaminated food; causes fever cramps
What are symptoms of gonorrhoea and how is it treated?
Causes thick discharge and pain when urinating. Treated with antibiotics and prevented with condoms.
What is rose black spot and how is it treated?
A fungal disease causing black spots on leaves reducing photosynthesis. Treated with fungicides or removing leaves.
What causes malaria and how is it spread?
Caused by protists transmitted by mosquitoes. Prevented by stopping mosquito breeding and using nets.
What are the symptoms of malaria?
Recurrent fever episodes; can be fatal.
What are the body’s non-specific defence mechanisms?
Skin nose hairs and mucus
What are the roles of white blood cells?
Phagocytosis antibody production
How does vaccination work?
Introduces inactive pathogens to stimulate antibody production; provides immunity if the pathogen re-enters.
What is herd immunity?
When a large proportion of the population is immunised it reduces pathogen spread.
What do antibiotics do?
Kill bacterial pathogens inside the body; must match the specific bacteria.
Why are viral diseases hard to treat with drugs?
Because viruses reproduce inside cells making it hard to destroy them without damaging body tissues.
What do painkillers do?
Relieve symptoms but do not kill pathogens.
Where were some drugs originally discovered?
Digitalis from foxgloves aspirin from willow
What are the stages of drug testing?
Preclinical (lab & animals) then clinical trials (humans)
What is a double-blind trial?
Neither the doctor nor the patient knows if they receive the real drug or a placebo.
How are monoclonal antibodies produced?
From hybridoma cells made by fusing mouse lymphocytes with tumor cells; cloned to make identical antibody-producing cells.
How can monoclonal antibodies be used?
In pregnancy tests lab tests
