Topic B3- Communicable Disease

• What is the topic of B2 in the study material?

  Infection and Response
• What are communicable diseases?

  Diseases that can be transmitted from one organism to another
• What are the types of pathogens mentioned in the study material?

  Bacteria, viruses, protists, and fungi
• How do bacteria affect the human body?

  They can make you feel ill by producing toxins that damage your cells
• How small are bacteria compared to the human body?

  Bacteria are very small living cells, much smaller than the size of your body
• What distinguishes viruses from bacteria?

  Viruses are not cells and are much smaller than bacteria
• How do viruses replicate inside the body?

  They live inside your cells and use the cell machinery to produce many copies of themselves
• What happens to the cell after a virus replicates inside it?

  The cell usually bursts, releasing all the new viruses
• What are protists?

  Protists are single-celled eukaryotes, and some can be parasites
• How do parasites affect their hosts?

  Parasites live on or inside other organisms and can cause them damage
• How are protists often transferred to their hosts?

  By a vector, which does not get the disease itself
• What are fungi and how do they vary?

  Fungi can be single-celled or have a body made up of hyphae
• How do hyphae affect human health?

  Hyphae can grow and penetrate human skin, causing diseases
• What do hyphae produce that can spread diseases?

  They can produce spores, which can be spread to other plants and animals
• What are the main ways pathogens can be spread?

  • Water: Contaminated drinking or bathing water
  • Air: Carried in droplets when coughing or sneezing
  • Direct Contact: Touching contaminated surfaces or skin
• How can cholera be transmitted?

  By drinking water contaminated with the diarrhoea of other sufferers
• How are airborne pathogens spread?

  They are carried in the air and can be breathed in
• What is an example of a disease spread by direct contact?

  Athlete's foot
• How is athlete's foot commonly spread?

  By touching the same things as an infected person, like shower floors and towels