Viral diseases

• What are viruses considered to be?

  Organisms
• How do viruses reproduce?

  By using another organism's cell machinery
• What happens when a virus reproduces inside a cell?

  The cell bursts, releasing new viruses
• Why do viruses make us feel ill?

  They damage our bodies during reproduction
• How is the measles virus spread?

  By droplets from coughing or sneezing
• What are common symptoms of measles?

  Red rash and high fever
• How common is measles in the UK?

  It's rare due to vaccinations
• How is HIV primarily spread?

  Through sexual contact and bodily fluids
• What does HIV stand for?

  Human immunodeficiency virus
• What does HIV do to the immune system?

  It causes a deficient immune system
• What are initial symptoms of HIV infection?

  Flu-like symptoms such as fever and tiredness
• What happens to the immune system as HIV progresses?

  It becomes weak, leading to infections
• What is AIDS?

  A disease where the immune system fails
• How did the prognosis for AIDS change with medication?

  People can live normal lives with treatment
• What is the name of the virus that affects plants?

  Tobacco mosaic virus
• What does the tobacco mosaic virus cause in plants?

  Mosaic patterns on leaves
• How does the tobacco mosaic virus affect photosynthesis?

  It reduces the plant's ability to photosynthesize
• What is the impact of the tobacco mosaic virus on plant growth?

  It prevents proper sugar production
• What are the key characteristics of viruses?

  • Not cells
  • Not living organisms
  • About 10,000 times smaller than animal cells
  • Cannot reproduce independently
• What is the process of viral infection and replication?

  1. Virus enters host cell
  2. Uses host's machinery to replicate
  3. New viruses are produced
  4. Host cell bursts, releasing viruses
  5. Viruses infect new cells