Grouping organisms

• There are seven biological functions that define living organisms and make them different from non-living things
• Characteristics of living organisms

  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion
  • Nutrition
• MRS GREN


  Mnemonic to remember the characteristics of living organisms
• Movement


  All living things move, including plants
• Respiration


  The chemical process which releases energy stored in food substances
• Respiration happens in all living cells, all of the time
• Released energy from respiration is necessary for growth and movement and all other life processes
• Glucose


  A simple form of sugar that breaks down with the intake of oxygen during respiration
• Respiration chemical reaction


  Glucose + oxygen → carbon dioxide + water + energy
• Breathing


  A physical process that happens in the lungs, bringing in oxygen needed for respiration
• Sensitivity


  Living things can sense changes in their environment
• Plants can bend towards a source of light
• Humans have five different senses to sense the world
• Human senses


  • Touch
  • Taste
  • Smell
  • Hearing
  • Sight
• Growth


  All living things grow
• Reproduction


  All living organisms have the ability to produce offspring
• Without offspring a species would be doomed for extinction
• Excretion


  The removal of toxic materials, waste products of metabolism, and substances in excess from the body of an organism
• Animals excrete waste products in their urine, sweat, faeces, and in the gases that they breathe out
• Nutrition


  All living things need food that releases the energy necessary for growing and development
• Autotrophic


  Plants make their own food using the Sun's energy through photosynthesis
• Types of animals based on diet

  • Herbivores
  • Carnivores
  • Omnivores
• Antibiotics


  Stop the spread of harmful bacteria
• Bacteria have evolved to withstand many antibiotics making them no longer effective in killing them
• Superbugs


  Bacteria that have become drug-resistant and are very hard to kill
• It is an ongoing battle for researchers to find and develop new antibiotics in a war against bacteria
• Viruses


  • Up to four times smaller than bacteria
  • Non-living things
  • Need a host to replicate
  • Most do not serve any useful purpose
• Not all viruses are harmful to humans
• Ways viruses can spread

  • Skin contact
  • Airborne
  • Found in milk
  • Animal bites
• Common carriers of viruses

  • Bats
  • Monkeys
  • Birds (including chickens)
  • Pigs
  • Horses
  • Dogs
  • Mice
  • Rats
• A virus cannot be killed by antibiotics because antibiotics only kill living organisms
• Strongest defence against a virus

  The body's own immune system
• Bacteria


  • Living microorganisms
  • Usually made of one cell
  • Show all seven processes of life
  • Multiply fast by dividing (fission)
• Individual bacteria can only be seen through a microscope
• Habitats where bacteria can live

  • Water
  • Soil
  • Inside living bodies
  • Inside dead bodies
• Most of the bacteria living inside our body are beneficial
• Beneficial bacteria


  Help digest food, turn milk into cheese or yoghurt, decompose dead things
• Bacteria have been used to make pickles, soya sauce, and vinegar
• Bacteria are used to break down sewage and to clean up oil spills
• Harmful bacteria can cause disease