Infection and Response

• What are pathogens?

  Microorganisms that cause infectious disease
• What types of microorganisms are classified as pathogens?

  Viruses, bacteria, protists, and fungi
• How can pathogens spread to plants or animals?

  Through direct contact, water, or air
• How small are viruses compared to other pathogens?

  Very small
• How do viruses replicate within a host cell?

  They use the cell's biochemistry to make copies
• What happens to the host cell when a virus replicates?

  The cell bursts, releasing copies into the bloodstream
• What symptoms arise from viral infections?

  Damage and destruction of cells make individuals feel ill
• How do bacteria reproduce?

  By dividing through binary fission
• What do bacteria produce that can harm cells?

  Toxins that can damage cells
• What is a characteristic of parasitic protists?

  They use hosts like humans and animals
• What are the structural forms of fungi?

  Single-celled or made of hyphae
• How do fungi reproduce?

  By producing spores that spread to organisms
• What are the main ways pathogens are spread?

  • Direct contact (e.g., touching contaminated surfaces)
  • By water (e.g., drinking dirty water)
  • By air (e.g., droplet infection from sneezing)
• How can pathogens be transmitted through water?

  By drinking or contacting dirty water
• How can the spread of disease be limited?

  • Improving hygiene (e.g., hand washing)
  • Using disinfectants
  • Isolating raw meat
  • Using tissues when sneezing
  • Reducing contact with infected individuals
• What hygiene practices can help limit disease spread?

  Hand washing and using disinfectants
• Why is it important to reduce contact with infected individuals?

  To limit the spread of pathogens
• Why are viruses particularly dangerous?

  They can enter all types of cells
• What are the symptoms of measles?

  Fever and red skin rash
• What complications can measles lead to?

  Pneumonia, encephalitis, and blindness
• How is measles spread?

  Droplet infection
• How is measles prevented?

  Vaccinations for young children
• What are the initial symptoms of HIV?

  Flu-like symptoms
• What does HIV lead to if untreated?

  AIDS, making the body susceptible to diseases
• How is HIV spread?

  By sexual contact or bodily fluids
• What are the prevention methods for HIV transmission?

  • Use condoms
  • Do not share needles
  • Screen blood for transfusions
  • Bottle-feed infants of HIV-positive mothers
• How can the development of AIDS be prevented?

  • Use antiretroviral drugs
  • Stop the virus from replicating
• What is the tobacco mosaic virus?

  A plant pathogen affecting many plant species
• What are the symptoms of tobacco mosaic virus?

  Discolouration of leaves
• How does tobacco mosaic virus affect plants?

  Reduces the yield by affecting photosynthesis
• How is tobacco mosaic virus spread?

  Contact between diseased and healthy plants
• How is tobacco mosaic virus prevented?

  Good field hygiene and pest control
• What is a major concern regarding bacterial diseases?

  They are becoming resistant to antibiotics
• What causes Salmonella food poisoning?

  Bacteria living in the gut of animals
• What are the symptoms of Salmonella food poisoning?

  Fever, stomach cramps, vomiting, diarrhoea
• How is Salmonella spread?

  Through raw meat and eggs
• What are the prevention methods for Salmonella food poisoning?

  • Vaccinate poultry against Salmonella
  • Keep raw meat away from cooked food
  • Wash hands and surfaces when handling food
  • Cook food thoroughly
• What are the symptoms of gonorrhoea?

  Thick yellow or green discharge and pain
• How is gonorrhoea spread?

  Through unprotected sexual contact
• What are the prevention methods for gonorrhoea?

  • Use contraception such as condoms
  • Antibiotics for treatment