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Flashcards · Biology

Health and Infectious Disease

96 cards from 6 lessons

  1. How does the WHO define health?

    A state of complete physical, mental and social well-being, not just the absence of disease.

  2. What is a communicable disease?

    A disease caused by a pathogen that can be spread.

  3. Give two examples of communicable diseases.

    Cholera, tuberculosis, malaria or HIV.

  4. What is a non-communicable disease?

    A disease that is not caused by a pathogen and cannot be passed on.

  5. Give two examples of non-communicable diseases.

    Cancer, heart disease, diabetes or cystic fibrosis.

  6. What is a pathogen?

    A microorganism that causes disease.

  7. Name four types of pathogen.

    Viruses, bacteria, fungi and protists.

  8. Why does HIV increase the risk of TB?

    It destroys white blood cells, so the immune system is weaker.

  9. How can a communicable disease cause a non-communicable disease?

    HPV infection can lead to cervical cancer.

  10. How does poor nutrition affect susceptibility to disease?

    It weakens the immune system.

  11. What is a positive correlation?

    As one variable increases, the other also increases.

  12. Does correlation prove cause?

    No. Other factors might affect both variables.

  13. Give two factors that affect health.

    Diet, stress, poverty, genes, or exposure to pathogens.

  14. Can mental health affect physical health?

    Yes. Stress can weaken the immune system.

  15. Is a person with no disease but who is lonely fully healthy, according to the WHO?

    No. Social well-being is also needed.

  16. Common mistake about non-communicable diseases?

    Saying they are caused by pathogens. They are not.

  17. Name the four types of pathogen.

    Viruses, bacteria, fungi and protists.

  18. Which is the smallest type of pathogen?

    A virus.

  19. Are viruses made of cells?

    No.

  20. How do bacteria reproduce?

    By dividing, which can happen as often as every 20 minutes.

  21. What is a toxin?

    A poison made by a pathogen that damages the host's tissues.

  22. What pathogen causes cholera?

    A bacterium, Vibrio cholerae.

  23. What is the main symptom of cholera?

    Severe watery diarrhoea, leading to dehydration.

  24. What pathogen causes tuberculosis?

    A bacterium, Mycobacterium tuberculosis.

  25. What does TB do to the body?

    It damages the lungs.

  26. What kind of organism causes Chalara ash dieback?

    A fungus.

  27. What are the symptoms of ash dieback?

    Leaf loss and lesions on the bark.

  28. What type of pathogen causes malaria?

    A protist, called Plasmodium.

  29. What does malaria damage?

    The blood and the liver.

  30. What does HIV destroy?

    White blood cells.

  31. What is AIDS?

    The stage when the immune system fails because of HIV.

  32. Common mistake about HIV and AIDS?

    Saying that they are the same. HIV is the virus, and AIDS is the condition that develops.

  33. How is cholera spread?

    In water that has been contaminated with sewage.

  34. Name two ways of preventing cholera.

    Clean drinking water and sewage treatment, or hand washing.

  35. How is TB spread?

    In droplets in the air from coughs and sneezes.

  36. Name two ways of reducing the spread of TB.

    Isolating infected people, ventilation, vaccination or treatment.

  37. How is Chalara ash dieback spread?

    By airborne spores, and on imported trees.

  38. How can the spread of ash dieback be slowed?

    Controlling imports, and destroying infected trees.

  39. What is a vector?

    An organism that carries a pathogen from one host to another.

  40. What is the vector for malaria?

    The female Anopheles mosquito.

  41. Name two ways of preventing malaria.

    Mosquito nets, killing mosquitoes or draining standing water.

  42. Why are insecticide-treated nets effective?

    They stop mosquitoes biting at night, and kill mosquitoes that land on them.

  43. Why does draining standing water help?

    Mosquitoes breed in water, so there are fewer of them.

  44. Why is TB spread more where there is overcrowding?

    There are more people to breathe in the infected droplets.

  45. What does the BCG vaccine protect against?

    Tuberculosis.

  46. Who showed that cholera spread through water in 1854?

    John Snow.

  47. Why does treating infected people reduce spread?

    They have fewer pathogens to pass on, so they are less likely to infect others.

  48. Common mistake about malaria?

    Saying that mosquitoes cause malaria. They carry the protist that causes it.

  49. What is an STI?

    An infection that is passed on by sexual contact.

  50. What causes chlamydia?

    A bacterium.

  51. Why can chlamydia spread widely?

    Many people have no symptoms, so they do not know they are infected.

  52. What can untreated chlamydia cause?

    Infertility, because of pelvic inflammatory disease.

  53. How is chlamydia treated?

    With antibiotics.

  54. What causes HIV?

    A virus.

  55. Name three ways in which HIV is spread.

    Sexual contact, sharing needles and from a mother to her baby.

  56. What does HIV do in the body?

    It destroys white blood cells.

  57. Is there a cure for HIV?

    No, but antiretroviral drugs control it.

  58. How does a condom reduce the spread of STIs?

    It stops body fluids passing between people.

  59. What is screening?

    Testing people with no symptoms to find an infection early.

  60. Why are needle exchange schemes used?

    So that people do not share needles, which spreads HIV.

  61. How can HIV be prevented from passing from mother to baby?

    Drugs for the mother, caesarean delivery, and avoiding breastfeeding.

  62. Why is donated blood tested?

    To stop HIV from being passed on in transfusions.

  63. Why do antibiotics not cure HIV?

    HIV is a virus, and antibiotics only work on bacteria.

  64. Common mistake about HIV?

    Thinking it can be caught by touching or hugging. It is spread through body fluids.

  65. What causes most stomach ulcers?

    The bacterium Helicobacter pylori.

  66. Where does H. pylori live?

    In the mucus lining of the stomach.

  67. How does H. pylori survive stomach acid?

    It makes an enzyme that produces ammonia, which neutralises the acid.

  68. How are stomach ulcers formed?

    The bacteria damage the lining, so acid and enzymes attack the exposed tissue.

  69. How does H. pylori spread?

    By oral transmission, in contaminated food, water or saliva.

  70. How is an ulcer caused by H. pylori treated?

    With antibiotics and a drug that reduces stomach acid.

  71. Who showed that H. pylori causes ulcers?

    Barry Marshall and Robin Warren.

  72. What did Marshall do to prove it?

    He swallowed a culture of the bacteria.

  73. What did doctors think caused ulcers before?

    Stress, spicy food and excess acid.

  74. What type of pathogen causes Ebola?

    A virus.

  75. What does Ebola cause?

    A haemorrhagic fever.

  76. How is Ebola spread?

    By contact with the body fluids of an infected person or animal.

  77. Name two ways of reducing the spread of Ebola.

    Isolating patients, protective clothing for health workers, safe burials or vaccination.

  78. Why is contact tracing important in an outbreak?

    It finds people who may be infected, so they can be watched and isolated.

  79. Is Ebola spread through the air?

    No. It spreads by direct contact with body fluids.

  80. Common mistake about ulcers?

    Saying that stress is the main cause. Most are caused by H. pylori.

  81. What is a virus made of?

    Genetic material (DNA or RNA) in a protein coat.

  82. Can a virus reproduce on its own?

    No. It needs a host cell.

  83. What is the protein coat of a virus called?

    The capsid.

  84. Why can a virus only infect certain cells?

    Its surface proteins only fit the receptors on certain cells.

  85. What are the stages of the lytic pathway?

    Attachment, entry, replication, assembly and lysis.

  86. What happens at lysis?

    The host cell bursts and releases new viruses.

  87. What happens in the lysogenic pathway?

    The viral DNA joins the host's chromosome and is copied when the cell divides.

  88. What is a provirus?

    Viral DNA that has been integrated into the host's chromosome.

  89. Does the host cell survive in the lysogenic pathway?

    Yes, and it divides normally.

  90. What can start the lytic pathway from the lysogenic one?

    A trigger, such as stress or damage.

  91. Why is a hidden virus difficult for the immune system to find?

    It is not making any viral proteins.

  92. Why do antibiotics not work on viruses?

    Viruses do not have the structures and processes that antibiotics attack.

  93. Which virus can hide in the lysogenic state and is not curable?

    HIV.

  94. How many viruses after 2 rounds if each cell releases 50?

    2500.

  95. What is the best way to prevent viral disease?

    Vaccination.

  96. Common mistake about viruses?

    Saying that they are living cells. They are not cells.