Mirco- o0rganisms

• Bacteria are prokaryotic cells that lack membrane bound organelles.
• Viruses are nonliving particles composed of nucleic acid (DNA or RNA) surrounded by protein coat, which can infect living cells to reproduce.
• Fungi are eukaryotes with cell walls made up of chitin instead of cellulose.
• Viruses are nonliving particles composed of nucleic acid (DNA or RNA) surrounded by protein coat, which can infect living cells to reproduce.
• Vaccination


  An effective means of stimulating active immunity
• Vaccine


  A substance that is injected into the body or given orally to prevent a specific disease
• The immune system protects the body by fighting disease-causing organisms such as viruses and bacteria
• Vaccination


  Speeds up the body's immune response to a specific disease-causing organism
• Vaccine


  Made from a weakened form of a disease-causing organism
• Tetanus vaccine


  • Contains the inactive form of the bacteria that causes tetanus
• Immune system response to vaccination

  1. Makes antibodies that will destroy any tetanus bacteria

  2. Lymphocytes recognise the bacteria quickly

  3. Lymphocytes multiply and destroy the bacteria before they have a chance to make you sick
• Reproduction


  The process by which a virus makes more copies of itself inside a living cell, using the cell's resources.
• Protein coat


  The protective layer surrounding the nucleic acid of a virus, which helps the virus attach to and enter host cells.
• Nucleic acid


  The genetic material of a virus, which can be either DNA or RNA.
• Viruses


  Nonliving particles composed of nucleic acid (DNA or RNA) surrounded by a protein coat, which can infect living cells to reproduce.
• Fungi


  A type of eukaryote with cell walls made of chitin instead of cellulose
• Eukaryote


  A type of cell that has a true nucleus and other membrane-bound organelles
• Chitin


  A polysaccharide made up of repeating units of N-acetylglucosamine
• Cellulose


  A polysaccharide made up of repeating units of glucose
• Vaccination


  The process of introducing a weakened or dead form of a disease-causing organism into the body, triggering an immune response and creating memory cells that protect against future infections.
• Immune response


  The body's natural defense mechanism against foreign substances, such as bacteria or viruses.
• Weakened or dead form


  In vaccination, a weakened or dead form of the disease-causing organism is used, so as not to cause the actual disease in the person being vaccinated.
• Triggering an immune response


  The weakened or dead form of the organism triggers the immune system to produce a response, resulting in the creation of memory cells that recognize and fight off the specific disease-causing organism in the future.
• Immunity in animals


  Animals have an internal immune system to defend themselves against micro-organisms, known as natural immunity
• Components of the immune system

  • Skin
  • Lymph system
  • Spleen
  • Bone marrow
• White blood cells (leucocytes)


  Manufactured by the immune system to destroy pathogens
• Types of leucocytes


  • Lymphocytes (B and T)
  • Phagocytes
• Antigens


  Foreign proteins that invade the body
• Immune response to antigens

  1. B-lymphocytes detect antigens and produce antibodies to destroy them

  2. T-lymphocytes destroy the antigens

  3. Phagocytes engulf the antigens through phagocytosis
• Active immunity


  The body makes antibodies through direct contact with pathogens
• Natural immunity is the inbuilt immune system found in animals to protect themselves
• Protein coat (capsid)


  The protective layer surrounding the nucleic acid of a virus, made up of multiple protein subunits arranged in a specific structure. It protects the viral genome from degradation and facilitates the entry of the virus into host cells.