infection and response

• Viruses are tiny particles that invade living cells and use them to multiply.
• White blood cells fight off pathogens by engulfing them or releasing chemicals called antibodies.
• Bacteria, fungi, protozoa, and worms can cause diseases.
• defense systems of the trachea: mucus, cilia,
• The lymphatic system is part of the body's defense against disease-causing organisms.
• Whats a virus? A small infectious particle that can only reproduce inside a living cell.
• comunicable disease: a disease that can be transmitted from one person to another
• Give three ways that white blood cells defend the body against pathogens: antitoxins, antibodies, ingesting them
• vaccines contain weakened or dead forms of viruses/bacteria that stimulate an immune response without causing illness
• the common cold is caused by rhinovirus
• measles is caused by measles virus
• What does being resistant to antibiotics mean: when germs like bacteria and fungi develop the ability to defeat the drugs
• suggest two possible reasons bacteria become resistant to antibiotics


  mutation and selection
• A person was injected with a vaccine. A few weeks later the person was exposed to the pathogen they had been immunised against.

  The graph shows how the concentration of antibodies in the blood changed after injection of the vaccine and after exposure to the pathogen.

  
• Describe in detail the differences between antibody production after the injection of the vaccine and after the person was exposed to the pathogen.

  antibodies release bcs of vaccine. Defeats it. Antibodies release bcs of pathogen.Defeats
• What is the primary role of white blood cells in the immune system?

  White blood cells help defend the body against pathogens by engulfing and destroying them, producing antibodies, and coordinating immune responses.
• Define vaccination.

  Vaccination is the process of introducing weakened or inactive forms of pathogens into the body to stimulate the immune system to produce antibodies and develop immunity against future infections.
• How do antibodies help in combating infections?

  Antibodies are proteins produced by white blood cells that recognize and neutralize specific pathogens or their toxins. They can bind to pathogens, mark them for destruction by other immune cells, and prevent them from infecting cells.
• What is the difference between active and passive immunity?

  Active immunity is developed by the body's immune system in response to exposure to a pathogen or through vaccination. Passive immunity occurs when antibodies are transferred from one individual to another, providing immediate but temporary protection.
• Describe the role of memory cells in the immune system:

  Memory cells are cells that have been activated by a previous encounter with a pathogen and can produce antibodies and cytokines
• What is the purpose of an inflammatory response during an infection?

  To destroy pathogens
• Explain the concept of herd immunity: When a large proportion of a population is immune to a disease, it is less likely to spread
• What are the differences between viruses and bacteria in terms of structure and replication? Structure: Virus - protein coat and genetic material; Bacteria - cell wall, cell membrane, and genetic material. Replication: Virus - requires a host cell to replicate; Bacteria - can replicate independently through binary fission.
• Explain the role of antibodies in the immune response.
• List all 4 types of pathogens: Bacteria Viruses Fungi Protists
• do viruses have nuclei? no, they have a single stranded RNA genome
• what is binary fusion?

  Cell division.
• definition of drug: a substance that can be used to treat or prevent disease
• What virus causes mosaic patterns on leafs? Tobacco mosaic virus (TMV)
• How does TMV spread between plants? Through sap
• cons of vaccines: side effects, allergic reactions, can't vaccinate everyone
• what can HIV do to the body? it can destroy white blood cells, which are important for fighting infection
• Label this white blood cell

  A) large nucleas

  B) Flexible Cell Membrane, easy to consume

  C) Lysosomes

  
• 2 types of white blood cells: phagocytes and lymphocytes
• list what phagocytosis is: engulfing and digesting foreign particles
• list what a lymphocyte is: a type of white blood cell that produces antibodies, nuetralise toxins, stick to pathogens and destroy them
• human defense systems

  Hair: Trap particles that could contain pathogens

  Skin: Acts as a barrier

  Trachea: Wafts mucus up the throat with cilia

  Stomach: Kills pathogens with acid
• List the stages of an immune response: exposure to antigen, activation of macrophages, production of antibodies by B-lymphocytes, destruction of pathogen by antibody coated phagocytes
• Deficiency disease: A disease caused by a lack of a nutrient in the diet.
• Infectious disease is a disease caused by a pathogen that is spread from one organism to another.