Communicable diseases

• What is a communicable disease?

  A disease that can be transmitted between organisms
• What is a pathogen?

  A microorganism that causes disease
• Name four types of pathogen.

  Bacteria, fungi, protists, viruses
• How can pathogens spread?

  Through air, water, and direct contact
• How do bacteria make you ill?

  They produce toxins that damage tissues
• How do viruses make you ill?

  They reproduce rapidly inside cells, damaging them
• What are four methods of controlling the spread of communicable disease?

  Good hygiene, isolation, controlling vectors, vaccination
• How can the cause of a plant disease be identified?

  Using gardening manuals, lab testing, monoclonal antibody kits
• What are three mechanical defences that protect plants?

  Thorns, drooping leaves, mimicry
• Give three physical defences of plants.

  Cellulose walls, tough cuticles, bark on trees
• How can aphids be controlled by gardeners?

  By introducing ladybirds to eat the aphids
• How can plant diseases be detected?

  By observing decay, discoloration, and growths