Communicable diseases

• What is a communicable disease?

  Disease caused by a pathogen
• A pathogen is a disease-causing microorganism
• Bacteria kill cells and produce harmful toxins.
• What is peer review in drug trials?

  Results checked by scientists
• In a single-blind trial, only the doctor knows if the patient receives the drug or the placebo
• In a double-blind trial, neither the doctor nor the patient knows who receives the drug or the placebo.
• What is used in preclinical testing to develop new drugs?

  Cells, tissues, live animals
• Match the quality of good medicine with its description:

  Effective ↔️ Works as intended

  Safe ↔️ No harmful side effects

  Stable ↔️ Retains its properties over time

  Able to be taken in and removed easily ↔️ Processed by the body
• Alexander Fleming discovered the antibiotic penicillin
• Aspirin originates from a compound found in willow bark.
• What do painkillers do to infectious diseases?

  Treat symptoms but don't kill pathogens
• Antibiotic resistance occurs when mutations lead to bacteria being resistant to an antibiotic
• Antibiotics cannot be used to treat viral diseases because viruses live inside host cells.
• What type of drugs are used to cure some bacterial diseases?

  Antibiotics
• Herd immunity occurs when a sufficiently high proportion of a population is immune to a disease
• Vaccinations stimulate white blood cells to produce antibodies.
• How do antitoxins protect against disease?

  Neutralise toxins
• Phagocytosis is the process where white blood cells called phagocytes ingest and destroy pathogens
• How does the respiratory system prevent pathogens from entering the body?

  Mucus and ciliated cells
• The skin acts as a physical barrier to prevent pathogens from entering the body.
• What type of pathogen causes malaria?

  Protist
• The rose black spot fungus is spread by wind and water
• Gonorrhoea is a sexually transmitted bacterial infection.
• How can the spread of salmonella be limited?

  Vaccinate animals, cook meat
• Tobacco mosaic virus causes leaf discolouration
• HIV is spread through direct sexual contact and exchange of bodily fluids.
• What condition results from a long-term HIV infection?

  AIDS
• Measles is spread by air through the inhalation of droplets
• Vaccination is one way to reduce the spread of pathogens.
• How do viruses cause disease?

  Invade and reproduce in cells