B3 - Infection and responses

• What are pathogens?


  Microorganisms that cause infectious disease, including viruses, bacteria, protists, and fungi.
• How do pathogens spread?


  They can spread through direct contact, water, or air.
• What is the size of viruses compared to other pathogens?


  Viruses are very small.
• What happens when viruses enter cells?


  They use the cell's biochemistry to make copies of themselves, leading to cell damage.
• What is the consequence of cell damage caused by viruses?


  The individual feels ill due to the destruction of cells.
• How do bacteria multiply?


  They multiply quickly through a process called binary fission.
• What do bacteria produce that can damage cells?


  Toxins that can harm cells.
• What are protists known for in relation to other organisms?


  Some are parasitic, using humans and animals as hosts.
• What are fungi composed of?


  They can be single-celled or made of hyphae, which are thread-like structures.
• How do fungi spread?


  They produce spores that can be spread to other organisms.
• What are the main ways communicable diseases are spread?


  • Direct contact (e.g., kissing, touching contaminated surfaces)
  • By water (e.g., drinking dirty water)
  • By air (e.g., droplet infection from sneezing or coughing)
• How can the spread of diseases be limited?

  By improving hygiene, reducing contact with infected individuals, removing vectors, and vaccination.
• What is one method to improve hygiene?

  Hand washing and using disinfectants.
• What is the purpose of vaccination?


  To make individuals immune to a disease before infection occurs.
• What are the symptoms of measles?


  Fever and red skin rash.
• How is measles spread?


  Through droplet infection.
• How is HIV primarily spread?


  By sexual contact or exchange of bodily fluids.
• What are the initial symptoms of HIV?


  Flu-like symptoms.
• What is the role of antiretroviral drugs in HIV treatment?


  They stop the virus from replicating in the body.
• What are the symptoms of Salmonella food poisoning?


  Fever, stomach cramps, vomiting, and diarrhoea.
• How is Salmonella spread?


  Through raw meat and eggs, and unhygienic conditions.
• What is the prevention method for Gonorrhoea?


  Using contraception such as condoms and antibiotics.
• What are the symptoms of Rose black spot?


  Purple or black spots on leaves, yellowing leaves, and early leaf drop.
• How is malaria spread?

  By the female Anopheles mosquito, which acts as a vector.
• What is the function of the skin in the human defense system?


  It acts as a physical barrier and produces antimicrobial secretions.
• What is one example of an antibiotic?


  Penicillin.
• What are the advantages and disadvantages of vaccination?


  Advantages:

  • Eradicated many diseases (e.g., smallpox)
  • Prevents epidemics through herd immunity

  
  

  Disadvantages:

  • Not always effective
  • Rare bad reactions (e.g., fevers)
• What is the concern regarding bacteria and antibiotics?


  Bacteria are becoming resistant to antibiotics.
• How can the development of antibiotic-resistant strains be prevented?


  By stopping overuse of antibiotics and finishing courses of antibiotics.
• What is the role of toxicity testing in drug development?


  To ensure the drug is safe for use.
• What is efficacy in drug testing?


  How well the drug carries out its role.
• What is the importance of dosage in drug development?


  To determine the correct amount of drug to administer.
• What is the significance of preclinical testing?


  To assess the safety and efficacy of drugs before human trials.
• What are the main components of the human defense system?

  • Non-specific defense system (skin, nose, trachea, stomach)
  • Specific immune system (white blood cells, antibodies, antitoxins)
• What is the great concern regarding bacteria and antibiotics?


  Bacteria are becoming resistant to antibiotics.
• How do mutations contribute to antibiotic resistance in bacteria?


  Mutations can occur during reproduction, allowing some bacteria to survive antibiotics.
• What happens to non-resistant bacteria when exposed to antibiotics?


  Non-resistant bacteria die when exposed to antibiotics.
• What is the consequence of resistant bacteria surviving and reproducing?


  The population of resistant bacteria increases, making antibiotics less effective.
• What are two methods to prevent the development of antibiotic-resistant strains?


  Stop overusing antibiotics and finish courses of antibiotics.
• Where were many drugs initially discovered?

  Many drugs were initially discovered in plants and microorganisms.