Bio B3 - Infection & response

• Health?

  Health is the state of physical and mental well-being.
• What is a pathogen?

  A microorganism that can cause disease
• Pathogens can cause communicable diseases, what is a communicable disease? Hence, what is a non-communicable disease?

  Communicable - An infectious disease
• List 4 different types of pathogens.

  -Virus

  -Fungi

  -Bacteria

  -Protists
• Give some examples of viruses also, what does a virus look like (picture a diagram in head)?

  -Measles

  -Rubella

  
• Give an example of a Fungi and what does a fungi pathogen look like?

  -Athlete's foot

  
• Give an example of bacteria and what does bacteria look like (picture in head)?

  -food poisoning (salmonella)

  
• Give an example of Protists and what does it look like (picture in head)?

  -Malaria

  (image not completely accurate. Outline is similar)

  
• List 3 facts about bacteria

  -very small cells

  -reproduces rapidly

  can produce toxins that damage your cells and tissues
• List 2 facts about viruses and then explain what a virus does inside the body to make people feel ill.

  -viruses are not cells

  -they reproduce rapidly

  -the virus invades the body cell, copies of the virus are made, new viruses burst out of the cell. They destroy cells and tissues thus causing us to feel ill.
• List 3 facts about Protisits

  -all Eukaryotes

  -majority are single-celled

  -often transferred by vector
• List 4 facts about fungi

  -some single-celled

  -or body made of hyphae (thread-like structures)

  -this hyphae can grow and penetrate skin, pants surfaces. causes diseases

  -can produce spores
• List the way diseases can spread, giver further examples of these ways.

  -Air; Colds, TB

  -Contaminated water; Cholera

  -Body fluid; AIDS, Chicken Pox, Cholera

  -Mother to unborn baby; Rubella

  -Vector;Insects or rats

  -Direct contact; Chicken pox, Athlete's foot,

  Rubella

  -Cuts/Sharing needles; AIDS, Tetanus

  -Contaminated food; food poisoning

  -Contaminated blood; AIDS
• How can we reduce the spread of diseases?

  -Simple hygiene measures; handwashing, tissues

  -Destroying vectors; pesticides, fuming mosquitos

  -isolation of infected individuals

  -vaccination
• Symptoms, mode of transmission, prevention and treatment of athletes foot

  Symptoms:

  -itchiness

  -scaliness

  -cracking skin

  
  

  Mode of Transmission:

  -direct contact

  
  

  Prevention:

  -don't share towels

  -no barefoot

  -dry properly

  
  

  Treatment:

  -anti-fungal creams

  -powders
• Same for Measles

  Symptoms:

  -Cold

  
  

  Transmission:

  -cough

  
  

  Prevention:

  -vaccination

  
  

  Treatment:

  -antibiotics
• Same for HIV

  Symptoms:

  -tiredness

  -weight loss

  -swollen

  -shortness of breath

  
  

  Transmission:

  -blood

  -bodily fluids

  -mother to unborn

  
  

  Prevention:

  -contraception

  -no sex

  
  

  Treatment:

  -antiviral medication
• Salmonella


  S:

  -vomiting

  -abdominal pain

  -headaches

  
  

  Trans:

  -contaminated food

  -expired food

  
  

  P:

  -cook food properly

  
  

  Treat:

  -drink lots of fluids

  -stay comfortable
• Malaria

  S:

  -fever

  -vomiting

  
  

  Transm:

  -vector;mosquito

  
  

  P:

  -mosquito nets

  
  

  Treat:

  -antimalarial medicine
• Cholera

  S:

  -vomiting

  -dehydration

  
  

  Transm:

  -contaminated water

  
  

  P:

  -clean water

  -vaccination

  
  

  Treat:

  -antibiotics
• what is a lymphocyte?

  a white blood cell
• What is phagocytosis?


  lymphocytes (white blood cells) engulf foreign cells (pathogen) and digest them
• what is an antigen

  certain chemicals produced by pathogens that are foreign to the body
• process of producing antibodies

  -lymphocyte sees antigen

  -starts too produce antibodies

  -pathogens attacked by the new antibodies
• antibodies are specific to the...

  antigen
• what do vaccines contain?

  -dead pathogens

  OR

  -live but weakened pathogens

  OR

  -parts of the pathogen
• what is herd immunity?

  when a large population is immune to the disease, the spread of the pathogen is reduced a lot and the disease may disappear
• antibiotic

  drugs that can kill bacteria (not viruses) inside the body
• antibodies

  Y-shaped protein made by white blood cells to destroy pathogens
• antigen

  a small protein marker on the outside of cells that allows lymphocytes to determine foreign cells
• phagocyte

  a type of lymphocyte that engulfs a pathogen and breaks it down
• Antibiotic resistance

  -mutation alters the bacterial DNA which makes a resistant strain of bacteria. causes of mutation ca be chemicals or radiation

  -antibiotics taken incorrectly weaker versions only are killed, leaving the stronger ore resistant bacteria. This is called natural selection

  -this means there is fewer bacteria remaining, ideal growing conditions and reduced competition = resistant bacteria population rapidly increases and spreads

  -therefore the whole populations becomes resistant the antibiotic becomes ineffective
• why do you need to do a drug trial?

  -determine side effects

  -safety

  -actually works
• what makes an effective drug?

  -doesn't stay in the body too long

  -no serious side effects

  -works and is safe
• what is a placebo drug?

  A fake version of the drug, has no effect on the body, a control in the experiment
• double blind trial

  -people who have the disease take part. some have placebo, real thing or previously invented treatment

  -even doctors don't know to prevent psychological bias
• memory cells


  cells which recognise a pathogen if it reinfects e body enabling fast response
• monoclonal antibodies

  antibodies produced artificially. a pure monoclonal antibody attacks only one type of cell or pathogen
• advantages of monoclonal antibodies

  -treatments for many diseases
• disadvantages of monoclonal antibodies

  -mice given tumours

  -transgenic mice

  -some death