B5

• What are communicable diseases caused by?

  Pathogens like bacteria and viruses
• How can communicable diseases be transmitted?

  They can be passed from one person to another
• What are non-communicable diseases?

  Diseases that cannot be transmitted between people
• How do pathogens make you feel ill?

  By damaging body tissues and producing toxins
• What are toxins?

  Poisonous substances produced by pathogens
• What are the five ways diseases spread?

  • Airborne
  • Food and waterborne
  • Insects and animals
  • Physical contact
  • Contact with body fluids
• What is the purpose of heating an inoculating loop in a Bunsen burner?

  To sterilise it before use
• How should the inoculating loop be used with bacteria suspension?

  Rub it onto the agar gel in zig zags
• Why is the lid of the petri dish sealed with tape?

  To prevent contamination and stop microbes escaping
• Why should the petri dish be stored upside down?

  To prevent condensation falling onto the gel
• What temperature range is ideal for bacterial growth?

  20-25°C
• Why should the temperature not exceed 35°C for bacterial cultures?

  Harmful bacteria grow best above body temperature
• What are the characteristics of different bacterial and fungal colonies?

  • Bacterial colonies: small, smooth, shiny
  • Fungal colonies: larger, fuzzy
• What are disinfectants used for?

  To destroy microorganisms on non-living objects
• What actions can people take to stop getting sick after the germ theory was accepted?

  • Maintain hygiene
  • Isolate infected individuals
  • Control disease-carrying vectors
  • Vaccination
• What types of cells can viruses infect?

  All types of cells
• What causes the symptoms of a viral disease?

  The body's reaction to viruses damaging cells
• Why is it important to stop the spread of viral diseases?

  Few medicines are available against viral diseases
• Why are viruses hard to treat with medicines?

  They are active inside the host cells
• What are all viruses classified as?

  Parasites
• How can some viruses remain inactive for years?

  They can be dried and stored as powder
• Name some viral diseases that affect humans.

  Common cold, influenza, smallpox
• What are the symptoms of measles?

  • Fever
  • Red skin rash
  • Can cause blindness and brain damage
  • Potentially fatal
• How is measles transmitted?

  By inhaling droplets from coughs and sneezes
• What is the only treatment for measles?

  Isolation of the patient and vaccination
• What does HIV infect?

  The immune system cells
• What condition does HIV lead to over time?

  AIDS
• How is HIV transmitted?

  Through direct sexual contact and body fluids
• What can happen to children born to infected mothers?

  They may be born blind
• What is Tobacco Mosaic Virus (TMV)?

  A virus affecting plants
• How does TMV affect plants?

  Destroys leaf cells, causing discolored patches
• Where is Salmonella commonly found?

  In the guts of many animals
• What can spread TMV?

  Contact and vectors like aphids
• What can Salmonella contamination cause?

  Food poisoning with fever and cramps
• How can Gonorrhea be transmitted?

  Through unprotected sexual contact
• What are the potential consequences of Gonorrhea?

  Pain, infertility, and ectopic pregnancy
• How can Gonorrhea be treated?

  With antibiotics
• What is a recent issue with Gonorrhea treatment?

  Strains have become antibiotic resistant
• What do crown galls result from?

  Bacterial infection in plants
• What do crown galls disrupt in plants?

  The plant's growth