GCSE AQA Biology Infection and 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 rapidlycan 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
• aseptic technique to grow uncontaminated samples of bacteria/culture microbes

  -dip inoculating loop in ethanol then hold it in fire until glowing;kills bacteria-dip loop in yeast, spread on the agar container-seal with tape on four corner-leave under 25 degrees Celsius heat
• Bacteria on a plate

  smooth circular colonies generally white, cream or yellow
• Yeast on a plate


  -type of fungus-looks similar to bacterial colonies but is pale and glossy
• Mould on a plate (fungi)

  -white/grey/black-fuzzy edges-range of colours from centre outwards-made out of filaments
• Symptoms, mode of transmission, prevention and treatment of athletes foot

  Symptoms:-itchiness-scaliness-cracking skinMode of Transmission:-direct contactPrevention:-don't share towels-no barefoot-dry properlyTreatment:-anti-fungal creams-powders
• Same for Measles

  Symptoms:-ColdTransmission:-coughPrevention:-vaccinationTreatment:-antibiotics
• Same for HIV


  Symptoms:-tiredness-weight loss-swollen-shortness of breathTransmission:-blood-bodily fluids-mother to unbornPrevention:-contraception-no sexTreatment:-antiviral medication
• Salmonella

  S:-vomiting-abdominal pain-headachesTrans:-contaminated food-expired foodP:-cook food properlyTreat:-drink lots of fluids-stay comfortable
• Malaria

  S:-fever-vomitingTransm:-vector;mosquitoP:-mosquito netsTreat:-antimalarial medicine
• Cholera

  S:-vomiting-dehydrationTransm:-contaminated waterP:-clean water-vaccinationTreat:-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
• define antiseptic

  chemical that kills microorganisms in the environment and safe for the skin
• 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