Infection and Response

• Pathogen


  Microorganism that causes disease (viruses, bacteria, fungi, protists)
• Bacteria


  Make you ill by producing toxins
• Viruses


  Make you ill by causing cell death when reproducing
• Measles


  Virus spread by liquid droplets in air or on surfaces, causes illness with symptoms like bad cold/cough, red eyes, rash
• HIV


  Virus that attacks white blood cells, can develop into AIDS which leaves you vulnerable to infections
• Body's defenses against pathogens

  • Stomach acid
  • Respiratory system mucus and hairs
  • Skin barrier
  • Tears in eyes
  • White blood cells consuming and destroying pathogens
  • Producing antitoxins and antibodies
• Aspirin was discovered from traditional ancient medicine
• Foxgloves are highly toxic but contain the heart drug digitalis
• Aphids devour plants


  Ladybirds and ants eat aphids, providing natural pest control
• Photosynthesis


  Takes water, carbon dioxide and turns it into oxygen and glucose
• Producing monoclonal antibodies


  1. Vaccinate mouse

  2. Collect spleen cells

  3. Fuse with cancer cell line

  4. Grow hybrid cells

  5. Separate antibodies
• Signs of plant diseases

  • Leaf discoloration
  • Black spots
  • Leaf loss
  • Loss of vigor
  • Abnormal flowers
  • Plant death
• Poor plant growth can also be due to nutrient deficiencies
• Nutrient deficiencies in plants

  • Low nitrates - poor growth, yellow leaves
  • Low phosphates - poor root growth, discolored leaves
  • Low potassium - poor flower and fruit growth
  • Low magnesium - yellow leaves