Biology

• Habitat


  The place an organism lives
• Population


  The total number of living organisms of one type in a habitat
• Community


  All the organisms living in a habitat
• Ecosystem


  Interacting communities, their habitats and the non-living components with which organisms interact
• Species


  Organisms that can interbreed and produce fertile offspring
• Biodiversity


  Variation of species in an area
• Niche


  The role an organism plays in its ecosystem
• Factors influencing an organism's niche


  • Resources required (E.g. light and nutrient availability)
  • Competition and predation
  • Interactions with others in community
  • Conditions (temperature)
• Predator


  Organism that obtains food by hunting and killing prey
• Prey


  Organisms that are hunted and killed by predator
• Carnivore


  Secondary consumer that eats primary consumers (meat)
• Omnivore


  Secondary consumer that eats both primary consumers (meat) and producers (plants)
• Herbivore


  Primary consumer that only eats plants
• Energy available at the next level of the food chain


  Energy used for growth
• Producer


  Organism that produces its own food
• Consumers


  Animals that can't make their own food so consume other organisms
• Food chain


  The arrows show the flow of energy throughout
• Food web


  A number of food chains joined together
• Pyramid of numbers


  Relative numbers of organisms at each level in a food chain
• A pyramid of energy can only have a regular pyramid, not an irregular one
• Energy loss in an ecosystem


  Undigested waste, movements and heat
• Biotic factor


  Factors related directly to living organisms
• Abiotic factor


  Non-living or physical factors which affect organisms
• Examples of biotic factors

  • Grazing
  • Competition
  • Predation
  • Disease
• Examples of abiotic factors

  • Light intensity
  • Soil moisture
  • pH
  • Temperature
• Competition


  Interaction between organisms seeking the same limited resources
• Intraspecific competition


  Organisms from the same species competing for resources
• Interspecific competition


  Organisms from different species competing for resources
• If grazing intensity is low


  Biodiversity in the area is high
• If grazing intensity is very high


  Biodiversity in the area is low
• If grazing intensity is medium/high

  Biodiversity in the area is high
• What plants compete for

  • Light
  • Water
  • Nutrients
• What animals compete for

  • Food
  • Shelter
  • Mates
• Thermometer


  Used to measure temperature
• pH meter


  Used to measure pH
• Moisture meter


  Used to measure moisture
• Light meter


  Used to measure light
• Quadrat


  Sampling technique used to sample plants
• Pitfall trap


  Sampling technique used to sample small animals in the soil
• Using a light meter


  Blocking sun and measuring at same time of day with no obstacles minimises error