Topic B3 - infection and response

• What are pathogens?

  Microorganisms that enter the body and cause disease
• What type of diseases do pathogens cause?

  Communicable (infectious) diseases
• Can both plants and animals be infected by pathogens?

  Yes, both can be infected by pathogens
• How small are bacteria compared to body cells?

  About 1/100th the size of body cells
• How do bacteria make you feel ill?

  By producing toxins that damage cells and tissues
• What are viruses compared to bacteria?

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

  They use the cell's machinery to produce copies of themselves
• What happens to the cell after a virus replicates inside it?

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

  Single-celled eukaryotes
• How can some protists cause damage to organisms?

  By living on or inside other organisms as parasites
• What are fungi made up of?

  Some are single-celled, others have a body made of hyphae
• How do hyphae cause disease?

  They can grow and penetrate human skin and plant surfaces
• How can spores spread disease?

  Spores can be spread to other plants and animals
• What are the main ways pathogens can be spread?

  • Water: Contaminated drinking or bathing water
  • Air: Airborne droplets from coughs or sneezes
  • Direct contact: Touching contaminated surfaces
• What is cholera?

  A bacterial infection spread by drinking contaminated water
• How is the influenza virus spread?

  Through airborne droplets produced when coughing or sneezing
• What is athlete's foot?

  A fungal infection that causes skin itching and flaking
• How can the spread of disease be reduced?

  By being hygienic, destroying vectors, isolating infected individuals, and vaccination
• What is Salmonella?

  A type of bacteria that causes food poisoning
• What symptoms are caused by Salmonella infection?

  Fever, stomach cramps, vomiting, and diarrhoea
• How can Salmonella be contracted?

  By eating contaminated food, such as undercooked chicken
• How is gonorrhoea transmitted?

  By sexual contact, such as unprotected sex
• What are the symptoms of gonorrhoea?

  Pain during urination and a thick discharge
• Why is treating gonorrhoea with penicillin becoming trickier?

  Because strains of the bacteria have become resistant to it
• How can the spread of gonorrhoea be prevented?

  By using barrier methods of contraception and treating infected individuals
• What hygiene measures can prevent the spread of disease?

  • Washing hands thoroughly before food preparation
  • Washing hands after sneezing
  • Keeping surfaces clean
• How can vectors be destroyed to prevent disease spread?

  • Using insecticides
  • Destroying their breeding habitats
• What is the role of vaccination in disease prevention?

  • Vaccination prevents individuals from developing infections
  • Reduces the chance of passing diseases to others
• What is measles?

  A viral disease spread by droplets from sneezes or coughs
• What are the symptoms of measles?

  A red skin rash and fever
• What can measles lead to if complications arise?

  Bronchopneumonia or inflammation of the brain
• What is HIV?

  A virus spread by sexual contact or exchanging bodily fluids
• What happens during the initial phase of HIV infection?

  It causes flu-like symptoms for a few weeks
• How can HIV be controlled in the body?

  With antiviral drugs that stop the virus from replicating
• What does HIV attack in the body?

  The immune cells
• What is late-stage HIV infection also known as?

  AIDS
• What is tobacco mosaic virus (TMV)?

  A virus that affects many species of plants
• What effect does TMV have on plants?

  It causes a mosaic pattern on the leaves, affecting photosynthesis
• What is rose black spot?

  A fungus that causes spots on rose plant leaves
• How does rose black spot affect plant growth?

  It reduces photosynthesis, leading to poor growth