Integrated Science

• Hygiene


  A practice of maintaining health and preventing disease through cleanliness
• Where hygiene can be practiced


  • Personal
  • Community
• Personal hygiene


  • Keeping yourself groomed
  • Washing hands after using the bathroom
  • Brushing teeth
• Community hygiene


  • Cleaning surfaces before and after food preparation
  • Removing litter
  • Preventing breeding grounds for pests
• Waste


  Anything that is not useful for you or to the organism
• Types of waste

  • Domestic
  • Industrial
  • Biological
• Sewage


  Waste from the removal of urine and feces from the body
• Sewage can cause infections and harbour harmful microorganisms
• Eutrophication


  Excessive growth of algae in water bodies due to high nutrient levels, blocking sunlight and oxygen
• Sewage treatment


  1. Sewage is carried to treatment plants

  2. Harmful substances are removed

  3. Remaining components are broken down and used, e.g. as fertilizer
• Ways to reduce waste

  • Reduce
  • Reuse
  • Recycle
• Parasite


  An organism that lives in or on another organism (the host) and gains nutrients from it, causing harm
• Pathogen


  A microorganism that causes disease, can be bacteria, protist, virus or fungi
• Vector


  An organism that carries and transmits a pathogen to a host, without being affected itself
• Pest


  A destructive insect or animal that can carry and spread disease-causing organisms
• Household pests


  • Rats
  • Roaches
  • Mice
  • Mosquitoes
  • Ants
• Proper hygiene practices, both in the home and community, are important to prevent pests
• Proper hygiene practices in the home and community are important to prevent pests
• If a person's home is clean but the surrounding community is not, pests can still enter the home
• Pests can find food, dark corners, and warm spaces to reproduce in homes that do not practice proper hygiene
• Methods to control pests

  • Physical barriers (e.g. screens, traps)
  • Chemical barriers (e.g. poisons, sprays)
• Mosquito and house fly life cycle

  1. Eggs

  2. Larvae

  3. Pupa

  4. Adult
• Methods to control mosquitoes at different life stages


  • Anti-larval measures (environmental, chemical, biological control)
  • Anti-adult measures (space sprays, residual sprays, genetic control)
• Methods to protect against mosquito bites

  • Mosquito nets
  • Protective clothing
  • Screens
  • Repellents
• Legislative control can be used to ensure people do not create breeding grounds for pests and face penalties
• Main methods of pest control

  • Sanitary control
  • Biological control
  • Chemical control
  • Mechanical control
• Electricity


  A form of energy resulting from the existence of charged particles, either through static accumulation or electric current
• Electric current


  The flow of charged particles along a complete path called an electric circuit connected to an energy source
• Electric circuit


  • Made of conducting material
  • Connected to an energy source
  • Must be complete with no open areas
• Ampere


  The unit of electric current
• Series circuit


  • Components connected one after the other
  • Total current from source is equal to current in each path
  • Break in one path stops current flow
• Parallel circuit


  • Components connected side-by-side
  • Total current from source is equal to sum of currents in each path
  • Break in one path does not stop current flow in other paths
• Voltage


  The electric potential difference between two points
• Voltmeter


  Instrument used to measure voltage, connected in parallel across a component
• Resistance


  The opposition to current flow in a circuit
• Ohm


  The unit of resistance
• Power


  The rate per unit time at which electrical energy is transferred by an electric current
• Direct current (DC)


  Current that passes around a circuit in one direction only, from a cell or battery
• Alternating current (AC)


  Current that passes around a circuit in one direction and then the opposite direction, from the mains supply
• Unit of power

  Watt (W), equal to 1 joule per second