biology chapter 5

• Communicable diseases are infectious diseases caused by pathogens, examples include measles and AIDS
• Non-communicable diseases cannot be passed from person to person
• Non-communicable diseases often last a long time and slowly get worse, examples include cancer and CHD
• Health affecting factors include: diet, stress levels, where you live, and financial situation
• Medical data is presented using scatter graphs, bar charts, histograms, and tables of raw data
• Bacteria are single-celled organisms

  <|>Some bacteria cause diseases, but many are harmless
• Some bacteria are useful for making cheese and beer
• Bacteria reproduce by dividing in half
• Viruses are even smaller than bacteria and not a complete cell

  <|>Viruses cause diseases such as flu, colds, chicken pox, mumps, and AIDS
• Viruses live inside cells, reproduce, damage, and destroy the cells
• Ways to prevent diseases include: hygiene, antiseptics, and vaccinations
• To reduce the spread of diseases, one can wash hands, cover mouth and nose, boil contaminated water, use insect repellent, and use hand sanitiser
• Ignaz Semmelweis was a doctor in the mid-eighties who noticed the connection between medical students dissecting and delivering babies
• Vaccinations involve introducing a small amount of a harmless (dead) specific pathogen into the body to prepare the immune system for future encounters with the live pathogen
• Vaccinations are effective for humans and animals, but not for plants as they lack an immune system