biology

• Living organisms


  • Plants
  • Animals
  • Microorganisms (microbes)
• Plants


  • Flowering plants
  • Non-flowering plants
  • Algae
  • Fungi
  • Bacteria
• Animals


  • Vertebrates
  • Invertebrates
• Common names


  Names used everyday for animals and plants, based on appearances which can be misleading
• Classification

  Putting things into groups
• Species


  The smallest group that an organism belongs to
• Genus


  Related species placed together
• Methods of classification


  • Morphological features (structure or appearance)
  • DNA analysis
• Kingdoms (morphological classification)


  • Bacteria
  • Plants
  • Fungi
  • Animals
  • Viruses
• Domains (DNA classification)


  • Bacteria
  • Archaea
  • Eukarya
• Binomial system


  Organisms given two names - genus and species
• The scientific/Latin name is the same all over the world and in all languages
• Example classification


  • Domestic dog
  • Coyote
  • Fox
• Arctic fox


  • Small ears to lose less heat
  • White coat for camouflage in snow
• Fennec fox


  • Large ears to lose more heat
  • Sandy cream coat for camouflage in desert
  • Nocturnal to avoid desert heat
• Morphological adaptations


  Adaptations in the shape/structure of an organism
• Behavioural adaptations


  Adaptations in the behaviour of an organism
• Organisms that are better adapted to the environment are more successful and usually reproduce more and have more offspring
• Predator


  Animals that kill and eat other animals
• Prey


  Animals that are eaten by predators
• Predator and prey populations

  There is a delicate balance between them
• Quadrat


  A square used to sample an area and count/measure organisms
• Using quadrats to study plant cover

  1. Place quadrat randomly

  2. Count number of each plant species

  3. Measure percentage cover of plants
• Finding total population size

  1. Take random samples in quadrats

  2. Calculate average number per quadrat

  3. Multiply average by total area
• Transect


  A series of quadrat samples taken in a line to study distribution of organisms
• Samples cannot be absolutely accurate, and scientists often use statistical analysis that takes account of sample size when drawing conclusions
• Capture-recapture technique


  1. Capture and mark a number of individuals

  2. Release them back

  3. Capture another sample later

  4. Use equation to estimate total population
• Biodiversity is the number of different species in a particular area
• Importance of biodiversity


  • Helps regulate atmosphere, water supply, nutrient cycles, provide fertile soil
  • Provides food, materials, medicines, human well-being
• Biodiversity is decreasing due to habitat destruction from human activities like building, quarrying, agriculture
• Methods to protect biodiversity

  • CITES (Convention on International Trade in Endangered Species)
  • SSSI (Sites of Special Scientific Interest)
  • Captive breeding programs
  • National Parks
  • Seed banks
  • Local biodiversity conservation schemes
• Computer programs can be used to model environmental interactions and predict trends like climate change, effects of pollutants, endangered species populations
• Biological control


  Using another organism (predator or parasite) to control a pest
• Example of biological control


  • Wasp laying eggs in whitefly larvae to control whitefly in greenhouses
• Advantages of biological control

  • Specific to particular pest
  • No need to re-introduce predator
  • Pest does not develop resistance
• Disadvantages of biological control

  • Delay before predator established
  • Predator may spread to other areas
• Whitefly


  A pest on tomato plants in greenhouses
• Biological control of whitefly


  1. Wasp lays eggs inside whitefly larvae

  2. Wasp eggs hatch and eat whitefly larvae

  3. Reduces whitefly population
• Biological control of whitefly

  • Only affects whitefly, no effect on other insects
  • Successful in greenhouses as a closed environment
• Biological control products


  • Encarsia Formosa